This contribution clarifies the procedural and substantive implications of the duty of sincere co-operation in order to identify the room of manoeuvre for individual Member States at the international stage. Based upon an analysis of the relevant case law of the European Court of Justice, it is argued that the implications of the loyalty principle essentially depend upon the particular context of the EU’s international involvement and, more specifically, upon the implications of a Member State’s intervention for the unity of the EU’s representation and the uniform application of EU law. Whereas this approach is instrumental to achieve the objectives of the EU’s external action as expressed in Article 21 TEU, it may nevertheless have certain paradoxical consequences from the perspective of the Member States.
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Judgment of 14 July 2005, Commission v Germany, C-433/03, EU:C:2005:462, paragraph 64.
Judgment of 20 April 2010, Commission v Sweden, C-246/07, EU:C:2010:203, paragraph 77.
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Significantly, in the pre-Lisbon context, the principle of genuine cooperation was only explicitly mentioned in Article 10 of the EC Treaty and thus, in theory, restricted to the former first pillar of the Union. Nevertheless, the Court in Pupino suggested that Article 10 TEC had a trans-pillar application, Judgment of 16 June 2005, Pupino, C-105/03, EU:C:2005:386, paragraph 42. The Treaty of Lisbon logically confirms this approach taking into account the formal abolition of the pillar structure, without however abandoning the special treatment of the former second pillar (Common Foreign and Security Policy), expressed in Article 24(3) TEU.
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This rule was already expressed in Opinion 2/91, where the Court observed that in situations where the EU cannot accede to an international agreement but its Member States can, “cooperation between the Community and the Member States is all the more necessary” where the Union must act “through the medium of the Member States”, Opinion of 19 March 1993, ILO Convention, 2/91, EU:C:1993:106, paragraph 36.
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See in this respect, AG Sharpston Opinion of 21 December 2016, Singapore FTA, 2/15, EU:C:2016:992, paragraph 77, where she observed that the Member States do not act “as a mere appendage of the European Union” in the ratification procedure of mixed agreements while also pointing out that the Member States would continue to be bound—as a matter of EU law—by the areas of the agreement falling under EU competence.
Judgment of 20 April 2010, Commission v Sweden, C-246/07, EU:C:2010:203, paragraph 104.
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AG Poiares Maduro Opinion of 20 April 2010, Commission v Sweden, C-246/07, EU:C:2009:589, paragraph 57.
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Judgment of 20 April 2010, Commission v Sweden, C-246/07, EU:C:2010:203, paragraph 102.
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Judgment of 2 June 2005, Commission v Luxembourg, C-266/03, EU:C:2005:341, paragraph 60 and Judgment of 14 July 2005, Commission v Germany, C-433/03, EU:C:2005:462, paragraph 66.
Judgment of 12 February 2009, Commission v Greece, C-45/07, EU:C:2009:81, paragraph 25 [emphasis added].
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Ibid. paragraph 58.
Ibid. paragraph 108.
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The impossibility for the Union to exercise its voting rights under the Stockholm Convention if any of the Member States exercises its right to vote is a clear example of such a situation.
See Judgment of 30 May 2006, Commission v Ireland (Mox Plant), C-459/03, EU:C:2006:345, paragraph 176.
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Van Elsuwege, P. (2019). The Duty of Sincere Cooperation and Its Implications for Autonomous Member State Action in the Field of External Relations. In: Varju, M. (eds) Between Compliance and Particularism. Springer, Cham. https://doi.org/10.1007/978-3-030-05782-4_13
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