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The Principle of Loyalty in EU Law$

Marcus Klamert

Print publication date: 2014

Print ISBN-13: 9780199683123

Published to Oxford Scholarship Online: April 2014

DOI: 10.1093/acprof:oso/9780199683123.001.0001

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Loyalty in the EU Treaties

Loyalty in the EU Treaties

(p.9) 1 Loyalty in the EU Treaties
The Principle of Loyalty in EU Law

Marcus Klamert

Oxford University Press

Abstract and Keywords

Chapter 1 discusses the origins of Union loyalty since the European Coal and Steel Community. It deals with specifications of loyalty in the Treaties that provide a ‘taste’ of its various functions in EU law, such as being the basis for mutual recognition. It explains how loyalty is relevant in all constellations under Union law, most commonly binding the Member States, but also applying in the reverse vertical relationship such as with preliminary rulings, horizontally between the Member States, and between the Union institutions in the shape of institutional balance. The Chapter discusses whether loyalty can also apply in areas of Member State competences, and to what extent it affects purely political matters and the cooperation of the Member States outside the framework of Union law or the Union institutions. This Chapter also deals with the relation between loyalty and the duty to respect national identities.

Keywords:   European Coal and Steel Community, preliminary rulings, national identities, institutional balance, mutual recognition

1. Introduction

The loyalty clause that I will discuss later is remarkable for several reasons: First, provisions on loyalty have been a constant element in the various EU Treaties, including the European Coal and Steel Community (ECSC) Treaty.1 Second, the wording of these provisions has barely changed since the 1950s and is thus very similar to what is currently stated in Article 4 (3) TEU. What has changed quite considerably, however, is the systematic context loyalty is placed in today. Third, the central loyalty clause has been complemented increasingly by various specifications of loyalty throughout the Treaties, some of which I will discuss later. Finally, the genealogy of Union loyalty apparently cannot be ascertained with certainty. The loyalty clause in Article 5 EEC that was adopted by the Rome Treaty and is discussed later had been inserted on the initiative of the German delegation and had been modelled after Article 86 ECSC.2 If the loyalty clause for the Community/Union was modelled after the one in the ECSC, this begs the question of the inspiration for the latter. I would suggest that what the drafters of the ECSC had in mind was a variation of the public international law principle of pacta sunt servanda.3 An indication of this perceived conventional nature of the loyalty clause is that in two books on the law of the ECSC, Article 86 is hardly mentioned or discussed in any depth.4 Moreover, according to the report of the French delegation, the provision should have a moral weight, but less a legal one.5

However, it is not too far-fetched a thought that the initiative of Germany with regard to the EEC also must be seen against the background of the German principle of federal fidelity (Bundestreue). I would suggest that it could hardly be a coincidence that, as I will show in Chapter 2, Bundestreue, while not expressly provided for in the German constitution, was first applied in the early 1950s by the German Constitutional Court.6 Indeed, as I will also show in Chapter 2, Union loyalty bears resemblance to both pacta sunt servanda and federal fidelity.

(p.10) 2. Loyalty before the Lisbon Treaty

The first important Treaty provision on loyalty was Article 86 of the now inexistent ECSC Treaty, which had the following wording:7

The Member States bind themselves to take all general and specific measures which will assure the execution of their obligations under the decisions and recommendations of the institutions of the Community, and facilitate the accomplishment of the Community’s purposes.

The Member States bind themselves to refrain from any measures which are incompatible with the existence of the common market referred to in Articles 1 and 4 …

The case law by the Court of Justice on this specific variation of loyalty in the Coal and Steel Community is partly still relevant today. The German proposal for Article 5 EEC seemed to be the reason for the only substantive difference between Article 86 ECSC and Article 5 EEC, viz. the substitution of the reference to the common market in the former by the references to the objectives of the Treaty in the latter.8 Article 5 EEC read:

Member States shall take all appropriate measures, whether general or particular, to ensure fulfilment of the obligations arising out of this Treaty or resulting from action taken by the institutions of the Community. They shall facilitate the achievement of the Community’s tasks.

They shall abstain from any measure which could jeopardise the attainment of the objectives of this Treaty.

In the EEC Treaty, loyalty had been situated in a slightly different context compared to today’s Lisbon Treaty. Article 4 EEC provided the general mandate to the institutions, coupled with the principle of conferral. Whereas this proximity between conferral and loyalty has been retained until today, Article 6 (1) EEC at that time foresaw the duty of coordination of economic policies between the Member States.9 Thus, Articles 4 to 6 in the EEC Treaty regulated the whole range of relationships that are still important in the European Union, both between the institutions and the Member States (conferral), vice versa (loyalty), as well as the relationship between the Member States themselves (coordination of economic policies).10

Before the Intergovernmental Conferences leading to the Maastricht Treaty, apparently, the Commission had tried unsuccessfully to expand the reach of loyalty by specifying national rules on failure to comply with Community law.11 Thus, what had been Article 5 EC became Article 10 EC, but remained otherwise unchanged compared to Article 5 EEC quoted earlier. Loyalty in the Treaty, thus, consisted of two indents, of which one prescribed a positive obligation (to act), while the other foresaw a negative obligation (to abstain).

Addressees were, prima facie, the Member States under Article 10 EC, which did not expressly impose mutual duties of assistance and cooperation that were also binding on the Union. In other words, Article 10 EC (and Article 5 EEC before it) by their wording only concerned the bottom-up, ‘vertical’ relationship, as opposed to a top-down, ‘reverse vertical’ relationship. Nonetheless, the Court extended loyalty also to the reverse (p.11) vertical sphere by imposing loyalty obligations on the Commission especially, as will be discussed later. In doing so, the Court has not been clear on the methodological approach chosen. In the leading case, the Court inferred duties of consideration incumbent on the Commission directly from ex Article 10 EC.12 In follow-up judgments, the Court in contrast spoke of ‘mutual duties of sincere cooperation’ imposed on the Member States by virtue of ‘[t]‌he principle to which Article 10 EC gives expression’,13 and of ‘mutual duties of sincere cooperation, as embodied in particular in Article 5 of the EEC Treaty’.14 This case law that was widely considered proof of the existence of a more general principle of Union law transcending the wording and scope of the Treaty provisions,15 has been codified by the Lisbon Treaty, as we will see in the following.16

3. The Lisbon Treaty Amendments

3.1 The Amended Loyalty Clause

In the Lisbon Treaty, the rule corresponding to Article 10 EC is now found in Article 4 (3) TEU and is worded as follows:

Pursuant to the principle of sincere cooperation, the Union and the Member States shall, in full mutual respect, assist each other in carrying out tasks which flow from the Treaties.

The Member States shall take any appropriate measure, general or particular, to ensure fulfilment of the obligations arising out of the Treaties or resulting from the acts of the institutions of the Union.

The Member States shall facilitate the achievement of the Union’s tasks and refrain from any measure which could jeopardise the attainment of the Union’s objectives.

An intricate question under the Nice Treaty had been whether loyalty in the Common Foreign and Security Policy (CFSP) was the same rule as in the other pillars.17 The removal of the pillar structure by the Lisbon Treaty and the shifting of the content of the former Article 10 EC to Article 4 (3) TEU now applies a concept of loyalty to the whole of European Union law. This ‘upgrading’ of loyalty might be an acknowledgement of case law such as Pupino.18 However, as we will discuss in the Part on Cohesion, also after Lisbon the TEU retains a separate regime on the CFSP, including specific and differently worded provisions on loyalty, which displays a strong basis in the principle of solidarity. It will thus be argued in Chapter 4 that the ‘unionization’ of loyalty has been codified with regard to the former third pillar, but that CFSP loyalty continues to be different from non-CFSP loyalty, also under the Lisbon Treaty.19 Indents 2 and 3 (p.12) are identical in wording to Articles 5 EEC and Article 10 EC, which has left them unchanged since the Rome Treaty. The only substantive modification therefore is to be found in the first indent of Article 4 (3) TEU,20 which codifies the duty of mutual assistance between the Member States established by Zwartveld.21 One might surmise that it would have been utterly unfeasible to codify everything that has been decided based on loyalty by the Court of Justice over the years. However, in the drafts drawn up by the Convention on the Future of the European Union, more substantive changes had still been contemplated.22

What is a novelty in the first part of Article 4 (3) TEU is the notion of ‘sincere cooperation’. It has been argued that this merely codifies one particular aspect of a broader principle of loyalty embodied by the entirety of Article 4 (3) TEU.23 However, this sentence marks the very beginning of a provision not divided into separate paragraphs. For this reason, the reference to the ‘principle of sincere cooperation’ could equally represent the title concept for the remainder of the duties contained in Article 4 (3) TEU. I would argue, firstly, that there is no difference between the notion of sincere cooperation and the notion of loyal cooperation under the Treaty. The ‘principle of sincere cooperation’ is rendered as ‘Grundsatz der loyalen Zusammenarbeit’ in the German version of the Treaty, and as ‘principe de coopération loyale’ in the French text.24 Secondly, I will argue later for considering duties of cooperation a subcategory of a more general principle of loyalty.

3.2 The New Article 13 (2) TEU

The newly worded Article 13 (2) TEU underlines the horizontal application of loyalty:

Each institution shall act within the limits of the powers conferred on it in the Treaties, and in conformity with the procedures, conditions and objectives set out in them. The institutions shall practice mutual sincere cooperation.

Article 13 (2) TEU, thus, expressly requires the institutions to display loyalty when exercising their powers, using the same language as provided in Article 4 (3) TEU on the mutual duties of Member States and Union institutions. Another similarity with Article 4 (3) TEU is the principle of conferred powers stated in both provisions.

Article 4 (3) TEU and its predecessors have never been construed by the Court as creating similar obligations for the relationship between the Union institutions themselves. The wording of ex Article 10 EC also did not easily lend itself to a construction that would not refer to the Member States. However, especially Cremona (p.13) had already argued that the principles of cooperation were not limited to Member States but would apply also to inter-institutional cooperation.25 I will argue later that loyalty in this relationship is embodied by the principle of institutional balance.

4. Specifications of Article 4 (3) TEU in the Treaties

4.1 Introduction

Loyalty in Article 4 (3) TEU is subsidiary to more specific Treaty provisions. In 1993, the Court held that ex Article 5 EEC ‘is worded so generally that there can be no question of applying it autonomously when the situation concerned is governed by a specific provision of the Treaty…’.26 Similarly, while Article 4 (3) TEU can be relied upon with regard to a breach of Union competence, if the competence concerned is of an exclusive nature, any reference to ex Article 10 EC is ‘merely a corollary’.27 Thus, the Court has explicitly mentioned this lex specialis nature with regard to ex Article 43 EC (now Article 49 TFEU) and the duty of mutual recognition.28 It has been argued that Article 106 (1) TFEU on public undertakings and undertakings to which Member States grant special or exclusive rights expresses a special duty of loyalty addressed to the states, viz. not to enact or to maintain in force any measure contrary to the Treaties.29 Moreover, while Article 288 TFEU is lex specialis to Article 4 (3) TEU for the duty of the Member States to take all measures required to implement Union directives, Article 291 TFEU is now the special provision for this duty with respect to other binding Union acts.30 Article 197 TFEU has introduced the proclamation that the ‘effective implementation of Union law by the Member States, which is essential for the proper functioning of the Union, shall be regarded as a matter of common interest’, which could arguably already be derived from Article 4 (3) TEU.31 Even Article 114 (4) and (5) on deviations from harmonization measures has been qualified as expressions of Article 4 (3) (p.14) TEU, establishing an obligation of the Member States to notify their measures to the Commission as soon as possible.32

Other pertinent examples are briefly discussed in the following. It will transpire that all of these provisions are examples of different facets of loyalty that are equally embodied by Article 4 (3) TEU proper; each of the provisions discussed illustrates and represents a distinct aspect of loyalty. While some of the provisions examined in the following cater to the ‘cooperative’ side of Union loyalty, others are rather expressions of its ‘confrontational’, conflict resolving side. These Treaty provisions therefore provide a sample of the wealth of effects loyalty has assumed over the course of the years since its introduction in the Rome Treaties.

4.2 Loyalty and Institutional Cooperation

The preliminary reference procedure pursuant to Article 267 TFEU is based on the cooperation between the Court of Justice and the national courts. Thus, we might say that the preliminary reference procedure, by its very nature as well as by its rules of procedure, embodies the loyalty principle in Union law.

Duties flowing from loyalty are also binding on national courts for matters within their jurisdiction.33 I would argue that national courts must exercise their powers in a way to avoid any significant risk of conflict in relation to decisions by the Union courts. Indeed, the Court has referred to the preliminary reference procedure as ‘an instrument of cooperation between the Court of Justice and national courts’.34 In this vein, the Court has held that both the national courts and itself must ‘make direct and complementary contributions to the working out of a decision’.35 In the CILFIT case, the Court emphasized that this obligation ‘is based on cooperation, established with a view to ensuring the proper application and uniform interpretation of Community law in all the Member States, between national courts, in their capacity as courts responsible for the application of Community law, and the Court of Justice’.36

It has been proposed that the need for this cooperation arises from two limitations of the Union system, viz. the lack of standing for individuals to bring appeals from national judicial decisions to the Court of Justice on the one hand, and the Court’s lack of coercive powers to enforce its judgments on the other.37 The first deficiency is closely related to the preliminary rulings procedure, which is the only (indirect) way for individuals to challenge national law.38 Dehousse has submitted that, on paper, Article 267 TFEU could have given rise to either a hierarchical model, in which the ECJ would have (p.15) tried to affirm its own superiority, or a cooperative model based on goodwill and mutual respect.39 At the same time, he also noted that the fact that ‘Article 177 is entirely dependent on the goodwill of national courts’ would militate for the cooperative model.40 I will return to the nature of the preliminary reference procedure in Chapter 11.

Bourgeois has also rightly remarked that Article 260 TFEU on the enforcement of EU law was in fact stating the obvious as far as the EU institutions are concerned and it was an application of the Community loyalty clause as far as Member States are concerned.41 AG Geelhoed has made the same observation, specifying that one link with loyalty would be the fact that a situation of illegality must be remedied, and the second would be that the balance of rights and obligations of the Member States under the Treaty must not be disturbed by a Member State arrogating a privileged position to itself in respect of the fulfilment of its Treaty obligations.42

4.3 Loyalty and the Resolution of Conflicts

We will find the conflict function of loyalty a recurring theme in this study. In the Treaty, it is represented by two leges speciales to Article 4 (3) TEU.

The obligation incumbent on Member States pursuant to Article 344 TFEU ‘not to submit a dispute concerning the interpretation or application of the Treaties to any method of settlement other than those provided for therein’ is a specific emanation of the general duty of loyalty contained in Article 4 (3) TEU.43 In the MOX Plant case, in response to the Commission’s claim that Ireland had failed in its duty of cooperation under ex Article 10 EC by bringing arbitral proceedings under the United Nations Convention on the Law of the Sea (UNCLOS) instead of bringing the case before the ECJ, the Court put this as follows:

The obligation devolving on Member States, set out in Article 292 EC, to have recourse to the Community judicial system and to respect the Court’s exclusive jurisdiction, which is a fundamental feature of that system, must be understood as a specific expression of Member States’ more general duty of loyalty resulting from Article 10 EC.44

The Court, consequently, did not find Ireland in breach of ex Article 10 EC, but only of ex Article 292 EC as regards the claim of starting arbitral proceedings.45 Although Article 344 TFEU does not deal with the classic form of norm conflict, it is a conflict clause nonetheless. The competence prerogative of the Court of Justice is safeguarded within the field of application of Union law against competing international fora for dispute resolution.46

(p.16) Article 351 TFEU (ex Article 307 EC) is concerned with the conflict of EU commitments with Member State agreements, and is perhaps the most complex of the specific expressions of loyalty in the Treaty.47 Article 351 TFEU is not about a transfer of competence from the Member States to the Union. It is concerned with conflicts between ‘obligations’ entered into by Member States vis-à-vis third states on the one hand with their obligations under Union law on the other, which are resolved in favour of the Union legal order.48 It provides that agreements concluded before 1 January 1958 by Member States with third states shall not be affected by the provisions of the Treaties. It continues:

To the extent that such agreements are not compatible with the Treaties, the Member State or States concerned shall take all appropriate steps to eliminate the incompatibilities established. Member States shall, where necessary, assist each other to this end and shall, where appropriate, adopt a common attitude …

Member States may be required by virtue of Article 351 (2) TFEU to renegotiate or even denunciate their treaties entering into force before 1 January 1958 or prior to a Member State’s date of accession.49 This may include that Member States would have to amend the respective treaty to enable conclusion by the Union.50 This role of Article 351 TFEU has been deemed an application of the general duty of cooperation laid down in Article 4 (3) TEU.51

As such, Article 351 TFEU is the logical complement to the conflict rules based on Article 4 (3) TEU.52

4.4 Loyalty and Duties of Abstention

Article 92 TFEU (ex Article 72 EC, ex Article 76 EEC) provides for a national standstill obligation in the shared area of transport policy until the Union has passed the measures foreseen under Article 91 TFEU. It prohibits Member States from discriminating directly or indirectly against carriers of other Member States, unless the Council unanimously grants derogation. Germany had introduced a tax on the use of roads for all heavy goods vehicles, but at the same time had reduced the general motor vehicle tax only for national carriers. In the ensuing infringement procedure, the Court found that ‘Article 76 of the Treaty seeks to prevent unilateral action by the Member States from making it more difficult for the Council to introduce the common transport policy, which constitutes one of the objectives of the Treaty listed in Article 3’.53 As such, the Court continued, ‘it constitutes the concrete expression in the sphere of transport of the general obligation, imposed on Member States by Article 5 of the Treaty, to abstain from any measure which (p.17) could jeopardize the attainment of the objectives of the Treaty’.54 Germany was found in breach of ex Article 76 EC only, without a need to ‘find a specific failure by that Member State to comply with Article 5 of the Treaty’.55

To bar national measures in the area of transport, which is a shared competence under Article 4 (1) (g) TFEU, without the existence of Union legislation, seems to de facto put Member States in the same position as in areas of exclusive competence, such as the Common Commercial Policy. Article 92 TFEU, however, does not bar any sort of transport-related measure by the Member States, but only such measures which are in some way discriminatory. It also includes a prohibition of merely abolishing existing privileges for foreign carriers, a practice that has unsuccessfully been argued in defence by the German Government in the earlier mentioned case.56 This makes it an expression of the general prohibition of discrimination now provided for in Article 18 TFEU, rather than of loyalty. Yet, what the objective Article 92 TFEU protects is the ability of the Union to regulate in the area of transport. This shall not be made more difficult by amendments to national laws which risk contradicting the fundamental Treaty principles.57 If the standard prohibition of discrimination was the only safeguard here, Member States could claim objective requirements to justify exceptions from this prohibition. This is not possible under Article 92 TFEU, from which the only possible derogation requires a (unanimous) Council decision.58 In further contrast to Article 92 TFEU, Article 18 TFEU does not bar Member States from putting an end to privileges of citizens of other Member States, as explained earlier.

Loyalty, thus, is not only a rule on conflicts between Union norms and Member State norms, but beyond that, a rule to protect the Treaty objectives even when they have not yet been transformed into legally binding acts, as I will discuss especially in Chapter 5.

4.5 Intervention: Combating Fraud

Article 325 TFEU prescribes that the Union and the Member States shall counter fraud and any other illegal activities affecting the financial interests of the Union. It can be understood as a specification of loyalty in two distinct ways. Article 325 (3) TFEU requires the Member States to ‘coordinate their action aimed at protecting the financial interests of the Union against fraud. To this end, they shall organize, together with the Commission, close and regular cooperation between the competent authorities’. Coordination here refers to the aim of abolishing legal and factual divergences between the Member States, which impede the effective combating of fraud.59 The cooperation between the national authorities required by Article 325 (3) TFEU implies the need to establish any necessary contact, exchange of information, and joint examination activities.60 Article 325 (3) TFEU, thus, represents the institutional, coordinative side of loyalty by requiring the actual cooperation of all parties concerned, similar to Articles 168 and 210 TFEU on health and development policy discussed later.

(p.18) Article 325 (2) TFEU requires Member States to ‘take the same measures to counter fraud affecting the financial interests of the Union as they take to counter fraud affecting their own financial interests’. This is an expression of the interventionist side of loyalty, which shapes the nature of national law for the aim of safeguarding the interests of the Union.61 There is an apparent relation with case law based on loyalty providing for a principle of equivalence when applying sanctions in national law in connection with breaches of Union law, dealt with in detail in Chapter 6. This relation is evidenced by a case on the improper use of Community funds.62 The Court could not apply Article 325 (2) TFEU, since this provision was not in force at the material time.63 It invoked ex Article 5 EC instead to require the Member States ‘to take all effective measures to penalise conduct harmful to the financial interests of the Community, whereby the penalty provided for must be analogous to those applicable to infringements of national law of similar nature and importance, and must be effective, proportionate and dissuasive’.64 At the same time, the Court held that the obligation under ex Article 5 EC is ‘underlined’ by what is now Article 325 (2) TFEU.65 It follows that, while Article 325 TFEU is the primary basis for such obligation in the present context, Article 4 (3) TEU can be referred to as a subsidiary legal basis.66

4.6 Conclusion

The specifications of loyalty in the Treaties discussed earlier tell us an important thing about loyalty, besides showing its diversity. What these provisions have in common is that loyalty is employed to protect a wide range of interests of the Union. It applies to avoid contradicting treaty commitments and prevents the undermining of the jurisdiction of the ECJ in Articles 349 and 351 TFEU. It safeguards the common market objective in the areas of the free movement of services by virtue of the principle of mutual recognition further explored later, and the objectives of Union transport policy under Article 92 TFEU. This ‘common’ Union interest, that is now explicitly mentioned in the lex specialis Article 197 TFEU, arguably is a general and pivotal point of reference for the application of loyalty especially in the field of external relations and will be analysed in detail in the Part on Cooperation, among others. Loyalty manifests itself as a duty of coordination in Articles 168 and 210 TFEU, as well as in Article 325 (3) TFEU. This will be discussed further in Chapter 8 with respect to non-exclusive competences. Its role in imposing certain standards on sanctions in national law pursuant to Article 325 (2) TFEU is a characteristic further explored in Chapter 6.

Notably, in all these aggregate states, loyalty has by far surpassed the wording of ex Article 10 EC. In the case of mutual recognition and policy area specific coordination, loyalty, for instance, is not primarily an obligation imposed on the Member States in their relation to the Union institutions, but creates obligations amongst the Member (p.19) States themselves. The amended basis of loyalty in Article 4 (3) TEU now better reflects this broad range of the addressees of loyalty, by explicitly referring to mutual duties of cooperation.

5. Loyalty and National Identities

While under the preceding Treaties it was a stand-alone provision, loyalty in Article 4 (3) TEU is now grouped together with two quite distinct provisions in Article 4 (1) and (2) TEU. I would argue that this has fundamentally changed the normative context loyalty is placed in compared to the Nice Treaty.67 Article 4 (1) TEU is the logical opposite to the conferral rule contained in Article 5 TEU, emphasizing that powers not conferred remain with the Member States.68 Article 4 (2) TEU is a partly novel provision safeguarding the Member States’ ‘national identities’, ‘their essential State functions’, and the area of ‘national security’.69 This is not the place to discuss exhaustively these new statements of reserved domains of the Member States.70 However, some comments are warranted in light of voices in the literature suggesting a certain relation between especially Article 4 (2) TEU and loyalty. Thus, Vedder has submitted that the respect of ‘national identities’ in Article 4 (2) TEU would be an emanation of the general principle of loyalty and that there would be a tension between this provision and the principle of solidarity.71 At the same time, he has claimed that the duty of cooperation between the Member States flowing from the general principle of loyalty is a specification of the solidarity between Member States.72 This, above all, demonstrates the need to explore whether there is a difference between solidarity and loyalty, which will be done in Chapter 2. Moreover, I would argue that if loyalty should thus be equivalent both to solidarity and to the protection of national identities, it defies logic to claim that there is a tension between solidarity and national identities. In any event, it is at odds with considering especially Article 4 (2) TEU on national identities well placed next to Article 4 (3) TEU on loyalty.73

Epiney has framed the concept now provided in Article 4 (2) TEU as an element of loyalty.74 She has argued that the respect for the federal structure of a Member State, notably of Germany, would ensure the attainment of Union objectives, since a Member (p.20) State, whose national constitutional identity was not respected by the Union, would cease to contribute to fulfilling the Union interest.75 Instead, such Member State would act in self-interest and obstruct the work of the Union as a reaction.76 I would proffer that it is somewhat circular to claim that by not respecting the particular interests of a Member State and because of that State’s ensuing act of defiance, the fulfilment of the objectives of the Union were jeopardized, which in turn would give rise to an obligation to protect national interests to prevent this from happening in the first place. Although, as I will explain later in this Chapter, loyalty in the European Union is not a one-way obligation and it is incumbent on the Union institutions to take into account interests of the Member States, the Court has applied this ‘reverse’ duty of loyalty only in specific, rather technical cases. As far as I can see, case law does not suggest that loyalty should oblige the Union, in a general manner, to take account of interests of individual Member States for preserving their national identity.77 Hence, it is for good reason that the Lisbon Treaty provides for a specific clause safeguarding the respect of national identities, since this arguably cannot be read into Article 4 (3) TEU proper. That this is done, however, next to the provision on loyalty, is difficult to understand, for the following reasons. As will be shown throughout this book, loyalty in manifold ways has the effect of furthering the integration of the Member States as constituent elements of the European Union, of providing the basis for all sorts of duties of cooperation, and of interlocking the legal regimes of the Member States with the Union. In short, loyalty expresses the gravitational force of European Union law.78 The reservations made in Article 4 (2) TEU represent rather the opposite idea of periphery, since, when understood extensively, they are another limit to the exercise of Union competence besides subsidiarity and proportionality.79 While loyalty, as I will argue later, is one of the foundations of supremacy, Article 4 (2) TEU has been qualified as a principle to oppose the supremacy of Union law.80 Craig has shown that the notion of ‘constitutional identity’ first appeared in a decision by the French Conseil Constitutionnel, where it served as a conflict resolution mechanism in favour of national interests.81 The safeguarding of national identities is perhaps an even more absolute limit than the mentioned principles of subsidiarity and proportionality, which both comprise a strong element of balancing the interests and capabilities of the Union with those of the Member States. Hence, Article 4 (2) TEU (p.21) might be a good match with the principle of conferral expressed in Article 4 (1) TEU, but less so with regard to loyalty.82

The connection between loyalty and Article 4 (2) TEU has also been made in the Lisbon judgment of the German Constitutional Court (BVerfG). In this judgment, which I will also discuss in Chapter 11, the BVerfG among other things reviewed ‘whether the inviolable core content of the constitutional identity of the Basic Law…is respected’.83 If Germany were to become a ‘constituent State of a European federal State’, this would amount to a change of the identity of Germany and a ‘loss of statehood’.84 This was claimed to follow the ‘principle of the Basic Law’s openness towards European Law (Europarechtsfreundlichkeit)’ and therefore not to contradict the principle of sincere cooperation provided in Article 4 (3) TEU. Without such review, according to the BVerfG, ‘the fundamental political and constitutional structures of sovereign Member States’ recognized by Article 4 (2) TEU could not be safeguarded.85 As argued, the principles enshrined in respectively Article 4 (2) and 4 (3) TEU are opposed to each other in a fundamental manner. If their application would have to be squared, this I would submit firstly cannot be the task of a national (constitutional) court, and secondly it cannot concern the review of provisions of an EU Treaty. Firstly, because if anybody would be entitled to review the claim of a violation of Article 4 (2) TEU, this would have to be the ECJ, not the respective national constitutional courts.86 This could entail from a request for a preliminary ruling regarding the interpretation of Article 4 (2) TEU by national constitutional courts, such as the BVerfG.87 Secondly, if Article 4 (2) TEU were to be applied, e.g. with a claim for annulment, this would have to relate to Union secondary law but not as a standard of review for provisions in another EU Treaty, as it was done by the BVerfG.

It has been argued, with reference to the pre-Lisbon provision of Article 6 (3) TEU, that the obligation under Article 4 (2) TEU is subordinate to the obligations of the Member States to respect the EU’s objectives in Article 3 TEU,88 and would thus also be subordinate to Article 4 (3) TEU. While it is not fully fathomable what the Court will make of Article 4 (2) TEU in the future, and whether it will not invoke it somehow offsetting the integrationist impetus that Article 4 (3) TEU possessed so far, it seems likely now that paragraph 2 will primarily be invoked in free movement and union citizenship cases in order to justify obstacles put up by Member States in defence of national interests.89 This would not directly place it in opposition to loyalty, but would (p.22) see its frame of application rather cabined by the principles governing the application of the fundamental freedoms.90 There is thus no indication now that the context the loyalty principle is placed in by the Lisbon Treaty should influence its scope or effect.

6. The Vectors of the Application of Loyalty

6.1 Horizontal Loyalty

With horizontal loyalty, I refer to obligations derived from Article 4 (3) TEU applying between the Member States.91 Thus, besides governing the (vertical) relationship between the Union institutions and the Member States, which is discussed later, the duties of cooperation such as those provided in Article 210 (1) TFEU on development cooperation and Article 168 TFEU on health policy concern the relationship between the Member States.92 Both provisions must be seen as an expression of a general obligation of loyalty.93 Another example is the provision in the earlier mentioned Article 351 TFEU on requiring Member States to assist each other ‘where necessary’ in eliminating incompatibilities between their ‘old’ treaties and Union law and to adopt a common attitude ‘where appropriate’.94

Another more intricate example of duties of loyalty applying to the relationship between the Member States is mutual recognition. This principle requires Member States to consider other Member States’ regulatory decisions in observance of the objective of the furtherance of the common market.95 The Professional Qualifications Directive 2005/36 enshrines this principle for established and non-established professionals.96 The fifth recital of the preamble of the precursor Directive confirmed the link between loyalty and the mutual recognition of diplomas. It stated that Member States would infringe ex Article 5 EC if they required a national of a Member State to produce diplomas (p.23) issued under the Member State’s own education systems, where that person has already acquired all or part of those qualifications in another Member State.97

It has been argued that mutual recognition would require all actors to take due account of the others’ legitimate interests in the exercise of their own competencies and functions, and that loyalty would embrace ‘the message that the EU legal system can be autonomous only to the extent it is accepted or mutually recognised by the other legal systems’.98 I would argue that one could adopt a broad or a narrow understanding of mutual recognition against this background.

The broad perspective is represented by the view of the Cassis de Dijon principle as a case of ‘judicial’ mutual recognition.99 As is well known, the Court was establishing the general prohibition of restrictions under the free movement of goods pursuant to Article 34 TFEU, allowing the free circulation of goods in the Union, provided they have lawfully been marketed in one Member State. A Member State, therefore, is required to accept the decision of other Member States on the quality and safety of goods as a matter of principle, except when it can invoke certain mandatory requirements as defined in Cassis. The German rule under review in Cassis de Dijon was assessed on its own, without looking for substantive functional equivalencies between home and host state rule.100

In contrast, a more narrow understanding would emphasize the mentioned close association between mutual recognition and loyalty, arguing for some degree of referral to the legal or factual situation in the home state, thus some degree of actual, factual cooperation on the side of the Member States.101 By this perspective, an automatism in co-opting regulatory decisions of other Member States, even if it only operates as a rule subject to exceptions such as in the Cassis de Dijon case law, would not qualify as mutual recognition.

6.2 Vertical Loyalty

On the part of the Member States, it is not difficult to identify the addressees of obligations based on loyalty. The main thrust of Article 4 (3) TEU and of loyalty clearly are obligations imposed on the Member States, as we will see throughout this book. Loyalty addresses all branches in the national state. The continued predominance of this vertical relationship is also reflected by the fact that the Lisbon Treaty has added only one paragraph not exclusively dealing with this vertical bond. A number of cases have clarified that not only the executive and legislative authorities of the Member States are bound by loyalty vis-à-vis the Union, but the national judiciary is bound as well.102 Since all (p.24) authorities of the Member States are required to ensure that the provisions of Union law take full effect, this also applies to national courts.103 Another case in point is the exclusive jurisdiction of the European Court of Justice over the interpretation of mixed agreements, discussed in detail in Chapter 10 in the Part on Cooperation. It has been written that ‘the interpretation the Court is called upon to give represents its contribution to the fulfilment of the duty of cooperation between institutions and Member States…’104

Loyalty applies to the Member States even when they act within their own competences, or when they operate outside of the Treaty entirely. Grabitz argued in 1992 that loyalty binds the Member States also within their own sphere of sovereignty, obliging them to act in a manner to further the interests of the Union.105 This is supported by case law on the duties of the Member States as parties to mixed agreements. This will be explored fully in Chapter 10. Suffice it to note here that in this context the Court has repeatedly held that the duty of cooperation applies ‘where it is apparent that the subject matter of an agreement or convention falls in part within the competence of the Community and in part within that of the Member States’.106 The Court also held that by ensuring respect for Union commitments the Member States ‘fulfil an obligation of Community law as well’.107 Thus, Member States are bound by Union law obligations and in particular by the duty of cooperation when they exercise their reserved competences within the context of a mixed agreement.108

Another example of loyalty’s application in matters of national competence is case law that curtails the freedom of the Member States with regard to their national tax laws. While the Member States, as a matter of principle, are entitled to levy taxes on reimbursements for expenses by the European Parliament to its Members from Union funds, such charges are not permissible when the payments cover expenses, even when payment is received as a lump sum. The Court decided that loyalty applies to national tax laws applicable to Members of the European Parliament and held that there is a ‘duty not to take measures which are likely to interfere with the internal functioning of the institutions of the Community’.109

(p.25) The vertical application of loyalty finds its limits with purely political matters. The Court held that Member States are not required to cooperate in the Council, to make compromises, or to form majorities when possible.110 Moreover, Member States are not obliged to act in the common interest or to refrain from pursuing national interests within the Union institutions.111 Thus, loyalty plays no role in protecting minority interests in the Council, nor does it require Member States to accommodate the positions of other Member States when voting.112 Moreover, loyalty cannot be invoked as the legal basis for obstructing majority decisions.113

I would argue that this ‘political exception’ within the Union institutions applies a fortiori outside the realm of Union law. Thus, the sanctions that were adopted by the (then seventeen) Member States against Austria in response to its far-right government involving Jörg Haider’s Freedom Party in 1999 should not be seen as an application of ex Article 10 EC.114 This would be different if one could argue that these sanctions jeopardized the interests of the Union. As the earlier discussion has shown, loyalty does not protect the interests of one Member State against the interests of other Member States, but it is primarily about the safeguarding of Union interests.115 Loyalty might therefore only have applied if the actions by the other Member States had affected the proper functioning of the Union or of its institutions. However, the sanctioning Member States apparently took great care to confine their actions to the bilateral level, such as sidelining Austrian representatives in diplomatic matters.116

6.3 Reverse Vertical Loyalty

While Member States are the foremost addressees of loyalty, Article 4 (3) TEU has always been employed by the Court to also prescribe mutual duties of cooperation between the Union institutions and the Member States and between the Union and Member State institutions.117 It has thus emphasized what is now explicitly stated in Article 4 (3) TEU, namely that loyalty rests on mutual duties, which bind not only the Member States but also the Union institutions. It has even been claimed that loyalty is equally strong when it applies to the Union institutions as when it binds the Member States.118 However, that this mutuality overall is asymmetrical is exemplified by the (p.26) fact that legislative action by the Council can never constitute a breach of ex Article 10 EC.119 This stands in stark contrast to lawmaking by the national legislators, which is one of the prime targets of the obligations under Article 4 (3) TEU.

The first statement ever by the Court on mutual duties of cooperation based on ex Article 5 EEC is made obiter in a case Luxembourg had brought against the European Parliament.120 This statement is confirmed by subsequent case law on the exercise of the powers of the Member States in relation to establishing the seat of the European Parliament. Because Strasbourg had been designated the provisional meeting place for the Parliament’s plenary sittings, France contested measures establishing plenary facilities in Brussels. The Court finely balanced its prescription. While it imposed a duty on the Parliament ‘to have regard’ to Member State powers for establishing the seat of the institutions and to the decisions taken provisionally by them in the meantime, the Court also required the Member States to respect the powers and the functioning of the Parliament in taking these decisions.121 This is a duty to consider the powers and thus the interests of the Member States in establishing the seat of the institutions. It is against the background of such duty of consideration that the Court affirmed the right of the Parliament to hold part-sessions away from Strasbourg if ‘such a decision remains exceptional in nature, thus respecting the position of that city as the normal meeting place, and is justified by objective reasons connected with the proper functioning of the Parliament’.122 According to Article 341 TFEU, the seat of the institutions of the Union is determined by ‘common accord’ of the governments of the Member States, which is subject to the application of Article 4 (3) TEU.123

The leading case for the reverse relationship regarding duties of loyalty is the quite peculiar case of Zwartveld.124 At issue was the request by the Dutch rechter-commissaris for the production of information and documents by the Commission for prosecuting fraud in connection with the EC fish marketing regulations. This rechter-commissaris was not a court within the meaning of ex Article 177 EEC (now Article 267 TFEU), cutting it off from the normal means of judicial dialogue in the EU.125 What followed was a decision to escape ‘the narrowness and inadequacies of positive law’ in order to safeguard loyalty and the protection of individual rights.126 The Court conspicuously took a deep argumentative breath, quoting Costa and Les Verts to make a general case for the existence of the rule of law in the European Union.127 The Court continued by invoking ex Article 5 (p.27) EEC in order to proclaim duties of the Commission vis-à-vis the rechter-commissaris, in spite of the privileges and immunities of the EC,128 with the following words:

This duty of sincere cooperation imposed on Community institutions is of particular importance vis-à-vis the judicial authorities of the Member States, who are responsible for ensuring that Community law is applied and respected in the national legal system.129

Loyalty here can be seen as applying to the Commission on the one hand and to the Court on the other. The Commission was not only ordered to produce any documents required by the rechter-commissaris, but also to have their staff testify before it. The Commission could only refuse to provide the pertinent information by claiming ‘imperative reasons relating to the need to avoid any interference with the functioning and independence of the Communities justifying its refusal to do so’.130 The Court of Justice considered itself bound to hear the request from the rechter-commissaris although technically it did not constitute a preliminary reference. We might therefore even say that Zwartveld applied loyalty in two ways, once in the form of the loyalty-based preliminary reference procedure, which was admitted in this case based on loyalty.131

While loyalty applies to all main organs of the Union apart from the Council, where the Court imposed duties of reverse loyalty, these were often a reflection and logical extension of distinct duties of cooperation on the part of the Member States. Thus, ex Article 100a (4) EC (now Article 114 (4) TFEU) was applied in combination with ex Article 10 EC to impose on Member States an obligation to notify provisions of national law that remain in force despite being incompatible with a harmonization measure.132 In exchange, the Court required the Commission to demonstrate ‘the same degree of (p.28) diligence and examine as quickly as possible the provisions of national law submitted to it’.133 In infringement proceedings, the inherent procedural bias against Member States is somewhat offset by the requirement that the Commission’s request for information on a specific charge must satisfy conditions of clarity and precision. While the Member States are, as I will discuss in Chapter 12, required to cooperate bona fide in any inquiry of the Commission and to supply it with all the necessary information,134 the Commission ‘must specify the acts or omissions which, in its opinion, constitute the infringement’.135 Moreover, also the Commission in the context of Article 17 (1) TEU must ‘take any steps which may facilitate mutual assistance between the Member States concerned and their adoption of a common attitude’.136

6.4 Institutional Loyalty

With institutional loyalty, I refer to obligations based on loyalty that apply between different Union institutions. This is now explicitly stated in the earlier mentioned Article 13 (2) TEU.137 I would suggest that loyalty in this constellation manifests itself in all variations of the principle of institutional balance. In contrast, it has been claimed that possible violations of institutional loyalty as provided under Article 13 (2) TEU should be resolved by applying the principle of proportionality.138 It seems, however, doubtful whether the balancing of interests of the institutions with the choice between several envisaged measures could be justiceable.

Institutional loyalty on the one hand concerns duties of inter-institutional dialogue especially in the co-decision procedure.139 Thus, the Court held that ‘inter-institutional dialogue, on which the consultation procedure in particular is based, is subject to the same mutual duties of sincere cooperation as those which govern relations between Member States and the Community institutions’.140 The Parliament was on this basis found to have ‘failed to discharge its obligation to cooperate sincerely with the Council’ when it did not appropriately react to a request for urgent debate by the Council.141

This, however, also concerns power struggles between the Council, the Commission, and the Parliament, mainly in the form of conflicts of legal bases.142 It can be argued (p.29) that inter-institutional conflicts are nothing but a conflict between the Union and the Member States, only that they are fought by substitutes.143 In most legal basis cases, the realization of the specific policy interests of the Member States will depend on whether the Council participates in lawmaking. This connection also reverberates in the leading case on institutional balance, stating that ‘each of the institutions must exercise its powers with due regard for the powers of the other institutions’.144

Portugal v Council seems to militate against such understanding of loyalty.145 In 1994, the Commission had signed with India and Pakistan respectively two ‘Memoranda of Understanding’ on arrangements in the area of market access for textile products containing a number of commitments by both the Union and the two countries mentioned. Portugal had openly opposed any such reciprocal concessions by the Member States other than those provided for in the World Trade Organization (WTO) Agreement on Textiles and Clothing. It claimed that the decision should not have been taken with majority voting but with unanimity.146 In its decision, the Court replied ‘that the principle of cooperation in good faith between the Community institutions and the Member States has no effect on the choice of the legal basis of Community legal measures and, consequently, on the legislative procedure to be followed when adopting them’.147 However, as shown earlier, the Court has never obliged Member States to cooperate within the Council. I would therefore submit that it is in keeping with this case law that the Court rejected the claim by Portugal in the pertinent case. Portugal v Council, thus, was not about a conflict of legal bases in the sense I will discuss in Chapter 11 as being partly resolved by considerations of loyalty.

7. Conclusion

It has been shown that loyalty is relevant in all constellations under Union law. It applies in the reverse vertical relationship between Union institutions and the Member States as well as between the institutions themselves. It binds Member States acting in not fully unionized fields of Union law as well as when they exercise their reserved competences in mixed agreements. More generally, I would argue that it has been shown that once Union interests are affected, loyalty applies irrespective of whether the matter belongs to the reserved powers of the Member States. This can concern the risk that obligations that the Member States have undertaken with their membership in the European Union are undermined or that the functioning of the institutions of the Union is jeopardized. In contrast, loyalty does not apply to agreements and cooperation of the Member States outside the framework of Union law or the Union institutions when this does not run counter to Union interests, such as with the case of the sanctions against Austria.


Loyalty in the EU Treaties

Figure 1.1 Union and National Actors Bound by the Union Interest

The above figure (Figure 1.1) summarizes the various actors that are bound to consider the interests of the Union in their relations with each other.

The specifications of Article 4 (3) TEU discussed earlier provide a ‘taste’ of the various and diverse functions of loyalty to be discussed in the next Chapters. Both the interventionist and the cooperative side of loyalty are reflected in the Treaties. What is reflected in neither the loyalty clause itself nor its specifications is the integrationist nature of loyalty. This has been exclusively relied upon by the European Court of Justice and will be discussed in Chapter 3 among others.


(1) M. Blanquet, L’Article 5 du Traité C.E.E.—Recherche sur les Obligations de Fidélité des États Membres de la Communauté (Paris: LGDJ, 1994), 5–6.

(2) Blanquet, L’Article 5 du Traité C.E.E., 8.

(3) See P. Mathijsen, Le Droit de la Communaute Europeenne du Charbon et de L’Acier: Une Etude des Sources (The Hague: Martinus Nijhoff, 1958), 28–29, on the absence of documents on the negotiations of the ECSC.

(4) See Mathijsen, Le Droit de la Communaute; W.J. Ganshof van der Meersch (ed.), Droit des Communautés européennes (Brussels: Larcier, 1969).

(5) A ‘portée morale, plus encore que juridique’. Quoted by K. Mortelmans, ‘The Principle of Loyalty to the Community (Article 5 EC) and the Obligations of the Community Institutions’, Maastricht Journal of European and Comparative Law, 5:1 (1998), 67–88, 67.

(6) Case 1 BvF 2/51 Finanzausgleichsgesetz [1952] BVerfGE 1, 117; Case 2 BvH 2/52 Wohnungsbauförderung [1952] BVerfGE 1, 299, 314.

(7) See Chapter 6.

(8) Blanquet, L’Article 5 du Traité C.E.E., 9.

(9) Art. 6 (1) EEC: ‘Member States, acting in close collaboration with the institutions of the Community, shall co-ordinate their respective economic policies to the extent that is necessary to attain the objectives of this Treaty.’

(10) See also Blanquet, L’Article 5 du Traité C.E.E., 10.

(11) D. Curtin, ‘The Decentralised Enforcement of Community Law Rights: Judicial Snakes and Ladders’, in D. Curtin and D. O’Keeffe (eds), Constitutional Adjudication in European Community and National Law (London: Butterworths, 1992), 33–49, 41.

(12) Case C-2/88 Imm. Zwartveld [1990] ECR I-3365.

(13) Case C-511/03 Ten Kate Holding [2005] ECR I-8979, para 28.

(14) Case 230/81 Luxembourg v European Parliament (Seat and Working Place of the Parliament) [1983] ECR 255, para 37.

(15) See Blanquet, L’Article 5 du Traité C.E.E., 291. See also J. Heliskoski, Mixed Agreements as a Technique for Organizing the International Relations of the European Community and its Member States (The Hague: Kluwer Law International, 2001), 64; M. Lück, Die Gemeinschaftstreue als allgemeines Rechtsprinzip im Recht der Europäischen Gemeinschaft: Ein Vergleich zur Bundestreue im Verfassungsrecht der Bundesrepublik Deutschland (Baden-Baden: Nomos, 1992), 23 with references to older German literature with the same tenor.

(16) In Chapter 13, I will return to the reasoning by the Court with general principles in general, and with loyalty as a general principle in particular.

(17) See on this A. Hatje, Loyalität als Rechtsprinzip in der Europäischen Union (Baden-Baden: Nomos, 2001).

(18) Case C-105/03 Pupino [2005] ECR I-5285.

(19) See Chapter 4 on the Structure of EU Law.

(20) W. Kahl, ‘Art. 4 (3) EUV’, in C. Calliess and M. Ruffert, EUV/AEUV: Das Verfassungsrecht der Europäischen Union mit Europäischer Grundrechtecharta, 4th edn. (Munich: Beck, 2011), para 86.

(21) Case C-2/88 Imm. Zwartveld [1990] ECR I-3365.

(22) The loyalty principle had been limited to the context of the exercise of competence, and the second indent had been placed in the context of the later abolished supremacy clause. In addition, an explicit extension of the scope of loyalty to local and regional public authorities had been discussed, as well as a specific duty of loyalty vis-à-vis the Member States and the Union for regions with legislative powers. See Kahl, ‘Art. 4 (3) EUV’, para 85 with further references.

(23) See C. Vedder, ‘Artikel I-5’, in C. Vedder and W. Heintschell von Heinegg (eds), Europäischer Verfassungsvertrag (Baden-Baden: Nomos, 2007), para 1.

(24) See A. Gamper, ‘On Loyalty and the (Federal) Constitution’, International Constitutional Law Journal, 4:2 (2010), 157, who notes that the German term is not common in German speaking countries, but seems to be a copy of the principle of ‘leale collaborazione’ provided in Art. 120 of the Italian Constitution. See also P. Unruh, ‘Die Unionstreue: Anmerkungen zu einem Rechtsgrundsatz der Europäischen Union’, Europarecht, (2002), 41–66.

(25) M. Cremona, ‘Defending the Community Interest: The Duties of Cooperation and Compliance’, in M. Cremona and B. de Witte (eds), EU Foreign Relations Law: Constitutional Fundamentals (Oxford and Portland, Oregon: Hart Publishing, 2008), 125–169, 157–158.

(26) Case C-18/93 Corsica Ferries [1994] ECR I-1783, para 18. See, in particular, Joined cases C-78/90 to C-83/90 Compagnie Commerciale de l’Ouest and Others [1992] ECR I-1847, para 19. See also Case C-35/88 Commission v Greece (Market in Feed Grain) [1990] ECR I-3125.

(27) Opinion of AG Tizzano in Case C-433/03 Commission v Germany (Inland Waterway) [2005] ECR I-6985, para 79; see also AG Léger in his Opinion in Case C-266/03 Commission v Luxembourg (Inland Waterway) [2005] ECR I-4805.

(28) Case C-31/00 Dreessen [2002] ECR I-663, para 30: ‘In the light of the foregoing considerations it does not appear necessary to interpret Article 10 EC, the interpretation of Article 43 EC alone being sufficient to provide the referring court with the reply that it needs.’ Less clear is Case 71/76 Thieffry [1977] ECR 765, paras 15–17. See also Case C-340/89 Vlassopoulou [1991] ECR I-2357, para 14, and Case 222/86 Unectef v Heylens [1987] ECR 4097, para 12. For a different perspective, see J. Snell, ‘Free Movement of Services and the Services Directive: The Legitimacy of the Case Law’, in J. van de Gronden (ed.), EU and WTO Law on Services (The Hague: Kluwer Law International, 2008), 31–54, 40–41, who goes to great lengths to rationalize mutual recognition in case law by resorting to the US Commerce Clause, among others.

(29) T. Bekkedal, ‘Article 106 TFEU is Dead: Long Live Article 106 TFEU!’, in E. Szyszczak et al. (eds), Developments in Services of General Interest (The Hague: TMC Asser, 2011), 61–102, 78, pointing to case law that prohibits Member States from enacting legislation that deprives the competition rules, which are directed at private undertakings, of their effectiveness.

(30) M. Ruffert, ‘Art. 291 AEUV’, in C. Calliess and M. Ruffert (eds), EUV/AEUV: Das Verfassungsrecht der Europäischen Union mit Europäischer Grundrechtecharta, 4th edn. (Munich: Beck, 2011).

(31) M. Nettesheim, ‘Art. 6 EUV’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäischen Union (Munich: Beck, 2011), para 27.

(32) C. Tietje, ‘Art. 114 AEUV’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäischen Union (Munich: Beck, 2011), paras 182–183, referring to Case C-319/97 Criminal Proceedings Against Antoine Kortas [1999] ECR I-3143. See note 133.

(33) See Case C-344/98 Masterfoods [2000] ECR I-11369, para 49. See further later in this Chapter on the addressees of loyalty.

(34) Case C-231/89 Krystyna Gmurzynska-Bscher v Oberfinanzdirektion Köln [1990] ECR I-4003, para 18.

(35) Case 16/65 Schwarze ECR 877, 886.

(36) Case 283/81 CILFIT [1982] ECR 3415, para 7.

(37) M. Cappelletti, The Judicial Process in Comparative Perspective (Oxford: Clarendon Press, 1989). See also J.H.H. Weiler, ‘A Quiet Revolution: The European Court of Justice and its Interlocutors’, Comparative Political Studies, 26:4 (1994), 510–534, 523, as a requisite of the Court’s power.

(38) On the political science aspects of preliminary references and judicial dialogue in general, see T. de la Mare, ‘Article 177 in Social and Political Context’, in P.P. Craig and G. de Búrca (eds), The Evolution of EU Law (Oxford: Oxford Univ. Press, 1999); A.-M. Slaughter, ‘A Typology of Transjudicial Communication’, University of Richmond Law Review, 29 (1994), 99–132.

(39) R. Dehousse, The European Court of Justice (London: St. Martin’s Press, 1998), 136–137.

(40) Dehousse, The European Court of Justice, 136–137.

(41) J.H.J. Bourgeois, ‘The European Court of Justice and the WTO: Problems and Challenges’, in J.H.H. Weiler (ed.), The EU, the WTO, and the NAFTA (Oxford: Oxford Univ. Press, 2001), 71–124, 94.

(42) AG Geelhoed in Case C-304/02 Commission v France (Fisheries) [2005] ECR I-06263, paras 5 and 8, referring to solidarity in this context, the relation of which with loyalty will be discussed in Chapter 2.

(43) C.-O. Lenz, ‘Art. 4’, in C.-O. Lenz and K.-D. Borchardt (eds), EU-Verträge, Kommentar nach dem Vertrag von Lissabon, 5th edn. (Cologne and Vienna: Bundesanzeiger Verlag, 2010), para 11.

(44) Case C-459/03 Commission v Ireland (MOX Plant) [2006] ECR I-4635, para 169.

(45) Note that the Court in this case also found a distinct breach of ex Art. 10 EC concerning the duties of Ireland to inform the Commission, which I will discuss in Chapter 12.

(46) See M. Cremona, ‘Disconnection Clauses in EU Law and Practice’, in C. Hillion and P. Koutrakos (eds), Mixed Agreements Revisited: The EU and its Member States in the World (Oxford and Portland, Oregon: Hart Publishing, 2010), 160–186, 179, who makes the valid point that, had a disconnection clause been included in UNCLOS preserving the autonomy of the Union legal order, the exclusive jurisdiction of the ECJ regarding a conflict between Ireland and the UK would have been much clearer.

(47) See J. Klabbers, Treaty Conflict and the European Union (Cambridge: Cambridge Univ. Press, 2009), 116–149.

(48) See M. Cremona, ‘Defending the Community Interest’, 132.

(49) See C-62/98 Commission v Portugal [2000] ECR I-5171, para 49.

(50) S. Lorenzmeier, ‘Art. 351 AEUV’, in E. Grabitz, M. Hilf and M. Nettesheim (eds), Das Recht der Europäischen Union (Munich: Beck, 2011), para 47.

(51) Joined opinion of AG Tizzano in the ‘open skies’ cases, [2002] ECR I-9427, para 38. According to AG Tizzano, if the first para of Art. 351 TFEU applies, a Member State’s failure to comply with the duty to cooperate in good faith amounts to an infringement of the second paragraph of Art. 351 TFEU.

(52) See also Chapter 14.

(53) Case C-195/90 Commission v Germany (Heavy Goods Vehicles) [1992] ECR I-3141, para 36. On this see C. Jung, ‘Art 92 AEUV’, in C. Calliess and M. Ruffert (eds), EUV/AEUV: Das Verfassungsrecht der Europäischen Union mit Europäischer Grundrechtecharta, 4th edn. (Munich: Beck, 2011), paras 2–6.

(54) Case C-195/90 Commission v Germany [1992] ECR I-3141, para 36.

(55) Case C-195/90 Commission v Germany [1992] ECR I-3141, para 38.

(56) See Jung, ‘Art 92 AEUV’, para 4.

(57) See D. Boeing, E. Kotthaus, and T. Maxian Rusche, ‘Art. 92 AEUV’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäische Union (Munich: Beck, 2012), para 1.

(58) Jung, ‘Art 92 AEUV’, para 8.

(59) See S. Magiera, ‘Art. 325 AEUV’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäische Union (Munich: Beck, 2012), para 33.

(60) See Magiera, ‘Art. 325 AEUV’, para 34, and paras 52–56 for the details of this cooperation.

(61) See Magiera, ‘Art. 325 TFEU’, para 7.

(62) Case C-186/98 Criminal Proceedings Against Maria Amélia Nunes and Evangelina de Matos [1999] ECR I-4883.

(63) AG Jacobs in Case C-186/98 Nunes [1999] ECR I-4883, para 9.

(64) Case C-186/98 Nunes [1999] ECR I-4883, para 14.

(65) Case C-186/98 Nunes [1999] ECR I-4883, para 13.

(66) Magiera, ‘Art. 325 TFEU’, para 8, has pointed to the wording ‘(w)ithout prejudice to other provisions of the Treaties’ in support of this claim.

(67) For a different perspective, see A. von Bogdandy and S. Schill, ‘Art. 4 EUV’, in E. Grabitz, M. Hilf and M. Nettesheim (eds), Das Recht der Europäische Union (Munich: Beck, 2010), para 1, who see the whole of Art. 4 TEU as the key for the federal structure of the union.

(68) Art. 4 (1) TEU.

(69) ‘The Union shall respect the equality of Member States before the Treaties as well as their national identities, inherent in their fundamental structures, political and constitutional, inclusive of regional and local self-government. It shall respect their essential State functions, including ensuring the territorial integrity of the State, maintaining law and order and safeguarding national security. In particular, national security remains the sole responsibility of each Member State.’

(70) See Lenz, ‘Art. 4’, paras 3–8; T. Konstadinides, ‘Constitutional Identity as a Shield and as a Sword: The European Legal Order within the Framework of National Constitutional Settlement’, Cambridge Yearbook of European Legal Studies, 13 (2010–2011), 195–218; L. Besselink, ‘National and Constitutional Identity before and after Lisbon’, Utrecht Law Review, 6:3 (2010), 36.

(71) C. Vedder, ‘Art. I-5’, in C. Vedder and W. Heintschell von Heinegg (eds), Europäischer Verfassungsvertrag (Baden-Baden: Nomos, 2007), para 1 and para 3.

(72) Vedder, ‘Art I-5’, para 18.

(73) But see Vedder, ‘Art I-5’, para 1.

(74) A. Epiney, ‘Gemeinschaftsrecht und Föderalismus: “Landes-Blindheit” und Pflicht zur Berücksichtigung innerstaatlicher Verfassungsstrukturen’, Europarecht, (1994), 301–324, 323. Agreeing with her, A. von Bogdandy, ‘Europäische Prinzipienlehre’, in A. von Bogdandy (ed.), Europäisches Verfassungsrecht: Theoretische und dogmatische Grundzüge (Heidelberg: Springer, 2003), 149–203, 202.

(75) Epiney, ‘Gemeinschaftsrecht und Föderalismus’, 317. In a similar sense, E. Grabitz, ‘Art. 5 EWGV’, in E. Grabitz (ed.), Kommentar zum EWG-Vertrag (Munich: Beck, 1992), para 17.

(76) Epiney, ‘Gemeinschaftsrecht und Föderalismus’, 317. Weiler’s metaphor of exit and voice comes to mind here. See J.H.H. Weiler, ‘The Transformation of Europe’, The Yale Law Journal, (1991), 2403–2483.

(77) See the discussion by M. Claes, ‘Negotiating Constitutional Identity or Whose Identity is it Anyway?’, in M. Claes et al. (eds), Constitutional Conversations in Europe: Actors, Topics and Procedures (Cambridge: Intersentia, 2012), 205–233, 226–227. Not even as a ‘lighter’ duty of consideration, as it has been put by A. Epiney, ‘Zur Tragweite des Art. 10 EGV im Bereich der Außenbeziehungen’, in J. Bröhmer and G. Ress (eds), Internationale Gemeinschaft und Menschenrechte: Festschrift für Georg Ress zum 70. Geburtstag am 21. Januar 2005 (Cologne: Heymanns, 2005), 441–459, 446.

(78) Loyalty has been argued to encompass the positive duty of Member States to avoid conflict, which might be relevant the more competences are conferred to the Union, thus reducing a ‘subsidiarian’ Europe. See Konstadinides, ‘Constitutional Identity’, 207–208.

(79) Vedder, ‘Art I-5’, para 3.

(80) F.C. Mayer, ‘Art. 19 EUV’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäischen Union (Munich: Beck, 2011), para 38.

(81) B. de Witte, ‘Direct Effect, Primacy and the Nature of the Legal Order’, in P.P. Craig and G. de Búrca, The Evolution of EU Law, 2nd edn. (Oxford: Oxford Univ. Press, 2011), 323–362, 355.

(82) Konstadinides, ‘Constitutional Identity’, 218, arguing that Art. 4 (2) TEU carries the potential of complementing the principle of conferral under Art. 5 TEU, ‘in that both provisions, in tandem, express the core of EU authority in the constitutional order of Member States’.

(83) Konstadinides, ‘Constitutional Identity’, 218.

(84) See, critical, D. Thym, ‘In the Name of Sovereign Statehood: A Critical Introduction to the Lisbon Judgment of the German Constitutional Court’, Common Market Law Review, (2009), 1795–1822, 1796. This implies a guarantee of Germany’s membership in a European Union as an association of sovereign states instead of as a federal state. See also Thym, ‘In the Name of Sovereign Statehood’, 1799.

(85) Case BvE 2/08 Lisbon.

(86) Mayer, ‘Art. 19 EUV’, para 90, has argued that identity control is not national law-centred since the respect of Member States’ ‘national identities, inherent in their fundamental structures, political and constitutional, inclusive of regional and local self-government’ is now explicitly provided by the Treaty. See also Claes, ‘Negotiating Constitutional Identity’, 207.

(87) See, in this sense, Mayer, ‘Art. 19 EUV’, para 91.

(88) Konstadinides, ‘Constitutional Identity as a Shield and as a Sword’, 199.

(89) See AG Maduro in Case C-213/07 Michaniki AE v Ethniko Symvoulio Radiotileorasis and Ypourgos Epikrateias [2008] ECR I-9999, para 33; Case C-208/09 Ilonka Sayn-Wittgenstein v Landeshauptmann von Wien [2010] ECR I-13693; Konstadinides, ‘Constitutional Identity as a Shield and as a Sword’, 201–204.

(90) Konstadinides, ‘Constitutional Identity as a Shield and as a Sword’, 207.

(91) See E. Schmidt-Aßmann, ‘Verwaltungskooperation und Verwaltungskooperationsrecht in der Europäischen Gemeinschaft’, Europarecht, 3 (1996), 270–301, 294, who has considered ex Art. 5 EC a sufficiently broad basis for a comprehensive regime of administrative cooperation.

(92) Art. 210 TFEU has the following wording: ‘(I)n order to promote the complementarity and efficiency of their action, the Union and the Member States shall coordinate their policies on development cooperation and shall consult each other on their aid programmes, including in international organisations and during international conferences.’

Art. 168 TFEU provides the following: ‘The Union shall encourage cooperation between the Member States in the areas referred to in this Article and, if necessary, lend support to their action…Member States shall, in liaison with the Commission, coordinate among themselves their policies and programmes in the areas referred to in paragraph 1…’ I will discuss both provisions in detail in Chapter 8 in the Part on Cooperation.

(93) See, for Art. 168, B. Schmidt am Busch, ‘Art. 168 AEUV’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäischen Union (Munich: Beck, 2011), para 26. See, for Art. 210, W. Benedek, ‘Art. 210 AEUV’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäischen Union (Munich: Beck, 2011), para 3.

(94) See S. Lorenzmeier, ‘Art. 351 AEUV’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäischen Union (Munich: Beck, 2011), para 39.

(95) See Case C-76/90 Säger [1991] ECR I-4221, para 15: ‘…in so far as that interest is not protected by the rules to which the person providing the services is subject in the Member State in which he is established.’

(96) Directive (EC) 2005/36 on the recognition of professional qualifications [2005] OJ L255/22. In areas not covered by this regime, the Court continues to apply the principle of equivalence introduced in Case C-340/89 Vlassopoulou [1991] ECR I-2357, para 14, which, in turn, was inspired by the forerunners to Dir 2005/36. See further P.P. Craig and G. de Búrca, EU Law: Text, Cases and Materials, 5th edn. (Oxford: Oxford Univ. Press, 2011), 812.

(97) See Case C-102/02 Beuttenmüller [2004] ECR I-5405.

(98) D. Curtin and I. Dekker, ‘The Constitutional Structure of the European Union: Some Reflections on Vertical Unity-in-Diversity’, in P. Beaumont, S. Lyons, and N. Walker (eds), Convergence and Divergence in European Public Law (Oxford and Portland, Oregon: Hart Publishing, 2002), 59–78, 70. See further Chapter 4 in the Part on Cohesion on this structural argument.

(99) J. Pelkmans, ‘Mutual Recognition in Goods: On Promises and Disillusions’, Journal of European Public Policy, (2007), 699–716, 702.

(100) See K. Armstrong, ‘Mutual Recognition’, in C. Barnard and J. Scott (eds), The Law of the Single European Market: Unpacking the Premises (Oxford and Portland, Oregon: Hart Publishing, 2002), 225–267, 233–235.

(101) See M. Klamert, ‘Of Empty Glasses and Double Burdens: Approaches to Regulating the Services Market à propos the Implementation of the Services Directive’, Legal Issues of Economic Integration, (2010), 111–132. See also Armstrong, ‘Mutual Recognition’, 230, who uses the term ‘other-regarding’.

(102) See the Opinion of AG Colomer in Case C-431/05 Merck Genéricos [2007] ECR I-7001, para 56. See also Joined cases C-300/98 and C-392/98 Dior [2000] ECR I-11307, paras 36-38; Joined cases C-261/07 VTB-VAB and C-299/07 Galatea [2009] ECR I-2949, para 39; Case C-106/89 Marleasing v Comercial Internacional de Alimentación [1990] ECR I-4135, para 8. See M. Cremona, ‘Defending the Community Interest’, 158, stressing that the duty of cooperation enshrined in Art. 4 (3) also applies to the cooperation between national courts and the Court of Justice.

(103) Case C-212/04 Adelener [2006] ECR I-6057, para 122.

(104) AG Tesauro in Case C-53/96 Hermès International [1998] ECR I-3603, para 21.

(105) See E. Grabitz, ‘Art. 5 EWGV’, in E. Grabitz (ed.), Kommentar zum EWG-Vertrag (Munich: Beck, 1992), para 1.

(106) See Ruling 1/78 IAEA [1978] ECR 2151, paras 34-36; Opinion 2/91 ILO [1993] ECR I-1061, para 36; Opinion 1/94 WTO [1994] ECR I-5267, para 108, and Opinion 2/00 Cartagena Protocol on Biosafety [2001] ECR I-9713, para 18.

(107) Case 104/81 Kupferberg [1982] ECR 3641, para 13. See I. Cheyne, ‘Haegeman, Demirel and their Progeny’, in A. Dashwood and C. Hillion (eds), The General Law of EC External Relations (London: Sweet & Maxwell, 2000), 20–41.

(108) See also C. Hillion, ‘Mixity and Coherence in EU External Relations: The Significance of the “Duty of Cooperation”’, CLEER Working Papers, 2 (2009), 21–26, who has argued that Member States must ‘fulfil all obligations they have undertaken so as not to compromise the Community’s position and the achievement of its objectives under the agreement, and if need be to cooperate with it to address possible compliance deficiencies’. Hillion mentions the example of a Member State’s breach of foreign and defence policy obligations flowing from a mixed agreement (a Member States competence), which could trigger the other party’s cross-retaliation in the form of a reduction or suspension of trade in goods manufactured in the defaulting state (an EU competence).

(109) Case 208/80 Lord Bruce of Donington [1981] ECR 2205, para 14; Case C-333/88 Tither [1990] ECR I-1133, para 16.

(110) Joined cases C-63/90 and C-67/90 Portugal and Spain v Council [1992] ECR I-5073, paras 52–53.

(111) Joined cases C-63/90 and C-67/90 Portugal and Spain v Council [1992] ECR I-5073, paras 52–53.

(112) See A. von Bogdandy, ‘Rechtsfortbildung mit Art. 5 EG-Vertrag’, in A. Randelzhofer, R. Scholz and D. Wilke (eds), Gedächtnisschrift für Eberhard Grabitz (Munich: Beck, 1995), 17–28, 27.

(113) See J. Wieland, ‘Germany in the European Union: The Maastricht Decision of the Bundesverfassungsgericht’, European Journal of International Law, 5 (1994), 259–266, 262, who discusses a statement by the BVerfG.

(114) But see P. Unruh, ‘Die Unionstreue—Anmerkungen zu einem Rechtsgrundsatz der Europäischen Union’, Europarecht, (2002), 41–66, 41–46. Instead, it has been argued that they constituted an unfriendly act under international law. See D. Richter, ‘Unfriendly Act’, Max Planck Encyclopedia of Public International Law (Heidelberg and Oxford: Oxford Univ. Press, 2013) (<http://www.mpepil.com>), para 25.

(115) When Member State interests have been considered by the Court, this was mostly done to counterbalance the pursuit of Union interests, such as in infringement proceedings. See Chapter 12.

(116) See Unruh, ‘Die Unionstreue’, 41.

(117) Joined cases 358/85 and 51/86 France v European Parliament [1988] ECR 4821, paras 34–35; Joined cases C-213/88 and C-39/89 Luxemburg v European Parliament [1991] ECR I-5643; Case C-275/00 Franex NV [2002] ECR I-10943, para 49; Case C-232/01 Criminal Proceedings Against Hans van Lent [2003] ECR I-11525, paras 72–77; Case C-234/89 Delimitis [1991] ECR I-935, para 53; Case C-344/01 Germany v Commission [2004] ECR I-2081, para 79.

(118) See Hillion, ‘Mixity and Coherence’, 29, who also relies on the IMO case, where the Commission was subjected to an obligation to consider the proposal by Greece in the Marsec. However, as I will explain in Chapter 12, this duty imposed on the Commission was very weak, and the Court found a violation of much stronger obligations flowing from ex Art. 10 EC against Greece.

(119) See, however, Joined cases C-63/90 and C-67/90 Portugal and Spain v Council [1992] ECR I-5073, paras 52–53.

(120) Case 230/81 Luxembourg v European Parliament (Seat and Working Place of the Parliament) [1983] ECR 255, para 37.

(121) Joined cases 358/85 and 51/86 France v European Parliament [1988] ECR 4821, paras 34–35.

(122) Joined cases 358/85 and 51/86 France v European Parliament [1988] ECR 4821, para 36.

(123) F.C. Mayer, ‘Art. 341 TFEU’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäischen Union (Munich: Beck, 2011), para 36.

(124) Case C-2/88 Imm. Zwartveld [1990] ECR I-3365.

(125) See B. de Witte, ‘Interpreting the EC Treaty Like a Constitution: The Role of the European Court of Justice in Comparative Perspective’, in R.C.L. Bakker, A.W. Heringa, and F.A.M. Stroink (eds), Judicial Control: Comparative Essays on Judicial Review (Antwerp: Apeldoorn, 1995), 133–152, 142.

(126) See G. Tesauro, ‘The Effectiveness of Judicial Protection and Co-operation between the Court of Justice and the National Courts’, Yearbook of European Law, (1993), 1–17, 12.

(127) Case C-2/88 Imm. Zwartveld [1990] ECR I-3365, paras 15–16. See the Court’s reasoning, in para 23, for affirming its jurisdiction ‘to review, at the request of a national judicial authority and by means of a legal procedure appropriate to the objective pursued by that authority, whether the duty of sincere cooperation, incumbent on the Commission in this case, has been complied with’.

(128) Protocol on the Privileges and Immunities of the European Communities, attached to the Treaty Establishing a Single Council and Single Commission of the European Communities of 8 April 1965. See P. Lasok, The European Court of Justice: Practice and Procedure, 2nd edn. (London: Butterworths, 1994), 575.

(129) Case C-2/88 Imm. Zwartveld [1990] ECR I-3365, para 18. See also Joined cases C-200/07 and C-201/07 Marra [2008] ECR 1, para 41. The Court in cases such as Case C-234/89 Stergios Delimitis v Henninger Bräu AG [1991] ECR I-935 applied this finding in Zwartveld in a more general mould, beyond the narrow facts of the case. See Case C-234/89 Delimitis [1991] ECR I-935, para 53: ‘Under Article 5 of the Treaty, the Commission is bound by a duty of sincere cooperation with the judicial authorities of the Member State, who are responsible for ensuring that Community law is applied and respected in the national legal system…’

(130) Case C-2/88 Imm. Zwartveld [1990] ECR I-3365, para 25. The Commission did invoke imperative reasons, without, however, much success. See C. Durand, ‘Le principe de coopération loyale entre les États membres et les institutions: les article 5 et 6 du traité CEE’, in Commentaire Megret, Vol. I, 2nd edn. (Brussels: Éditions de l’Université de Bruxelles, 1992), 25–42, 41. See also Case C-275/00 Franex NV [2002] ECR I-10943, para 49; Case C-232/01 van Lent [2003] ECR I-11525, paras 72–76. This is a parallel to the case law regarding the duties of the Parliament discussed earlier. Despite the different quality of cooperation concerned, in both constellations the Court applied ‘objective reasons’ and ‘imperative reasons’, respectively. With the Parliament, these set the limit for the freedom of its actions, and thus further defined its duty of consideration, whereas with the Commission, the imperative reasons equally limited the extent of its obligations, yet in a clearer rule-exception way than in the case of the Parliament.

(131) See also Durand, ‘Le Principe de Cooperation Loyale’, 41: ‘En outré, le Président a assurément considéré la Cour comme tenue elle-même par l’obligation de coopération loyale, en accueillant la “demande d’entraide judiciaire” soumise par le tribunal néerlandais, qui n’entrait dans aucune des catégories classiques de cas de saisine.’ For a different perspective, see von Bogdandy and Schill, ‘Art. 4 EUV’, para 107. See also G. Bebr, ‘Court of Justice: Judicial Protection and the Rule of Law’, in D. Curtin and T. Heukels (eds), Institutional Dynamics of European Integration: Essays in Honour of Henry G. Schermers, Vol. II (Dordrecht/Boston/London: Martinus Nijhoff, 1994), 303–333, 323–327, who stresses that the request for assistance in this case should not be confused with a request for a preliminary ruling which was limited to questions of validity and interpretation.

(132) Case C-319/97 Criminal Proceedings Against Antoine Kortas [1999] ECR I-3143.

(133) Case C-319/97 Kortas [1999] ECR I-3143.

(134) See note 197.

(135) See, to that effect, Case 192/84 Commission v Greece (Credit Terms) [1985] ECR 3967, para 20. See also the Opinion of AG Darmon in Case 192/84 Commission v Greece [1985] ECR 3967, at p 3972; Opinion of AG Poiares Maduro in Case C-82/03 Commission v Italy [2004] ECR I-6635, para 8.

(136) Case C-205/06 Commission v Austria (BITs) [2009] ECR I-1301, para 44.

(137) See Cremona, ‘Defending the Community Interest’, 157–158, arguing that ‘the principle of cooperation is not limited to Member States, and also applies to inter-institutional cooperation’. See also C. Hillion, ‘Tous pour un, un pour tous!: Coherence in the External Relations of the European Union’, in M. Cremona (ed.), Developments in EU External Relations Law (Collected Courses of the Academy of European Law: Oxford Univ. Press, 2008), 10–36, 30–31, who, based on ex Art. 3 TEU, has argued that the Council and the Commission must ensure the consistency of the Union’s external activities and that they must cooperate to this end. Most commentaries on ex Art. 10 EC or on Art. 4 (3) TEU do not mention this constellation as an application of duties of cooperation. But see now M. Nettesheim, ‘Art. 13 AEUV’, in E. Grabitz, M. Hilf, and M. Nettesheim (eds), Das Recht der Europäischen Union (Munich: Beck, 2011), para 79.

(138) See Nettesheim, ‘Art. 13 AEUV’, para 79.

(139) K. Lenaerts and P. Van Nuffel with R. Bray and N. Cambien (eds), European Union Law, 3rd edn. (London: Sweet & Maxwell, 2011), 153–154.

(140) Case C-65/93 European Parliament v Council [1995] ECR I-643, para 23. See also Case 204/86 Greece v Council [1988] ECR 5323, para 16.

(141) Case C-65/93 European Parliament v Council [1995] ECR I-643, para 27.

(142) Institutional balance has, however, more often been discussed in the context of cases of institutional self-empowerment. See Case C-70/88 Parliament v Council (Chernobyl) [1990] ECR I-2041; Case C-133/06 Parliament v Council (Delegation of Legislative Power) [2008] ECR I-3189. See Lenaerts and Van Nuffel with Bray and Cambien, European Union Law, 155, who under this title discuss also case law requiring the Member States to refrain from taking measures that might jeopardize the institutions’ independence.

(143) See also K. Lenaerts, ‘EU Federalism in 3-D’, in E. Cloots, G. de Baere, and S. Scottiaux (eds), Federalism in the European Union (Oxford and Portland, Oregon: Hart Publishing, 2012), 13–44, 24.

(144) Case C-70/88 Parliament v Council (Chernobyl) [1990] ECR I-2041, para 22.

(145) Case C-149/96 Portugal v Council (Textiles) [1999] ECR I-8395.

(146) Portugal had also claimed that this disregard of its interests by the other Member States deciding with qualified majority under former Art. 133 EC (now Art. 207 TFEU) was in breach of the principle of cooperation in good faith.

(147) Case C-149/96 Portugal v Council (Textiles) [1999] ECR I-8395.