124 5 Swider and den Heijer Questions of Competence, Legal Basis and Subsidiarity Yet, the proposition that the Union is well placed to legally act on statelessness must overcome concerns relating to the division of competences between the Union and the Member States. Existing literature which touches on the EU’s potential to act on statelessness points to two obstacles in this respect.89 The first is that any legislative action is likely to intervene in the sovereign prerogatives of the Member States in the area of nationality laws. Second, it has been submitted that there is no legal basis in EU treaties for regulating the legal position of stateless persons as such. We will address these concerns in turn and will also say a few words about why our proposal complies with the Union’s subsidiarity principle. 5.1 Member States’ Prerogatives in Nationality Matters The Member States have been protective of their sovereignty in nationality matters ever since the concept of Union citizenship started to take ground. The crucial disclaimer to Union citizenship, laid down in Art. 20(1) TFEU, is that ‘[c]itizenship of the Union shall be additional to and not replace national citizenship’. The caveat has been in force since the 1997 Treaty of Amsterdam, albeit in slightly different wordings.90 When the Treaty of Maastricht first introduced the concept of European citizenship into the Treaties in 1992, Member States were adamant to claim ownership over nationality matters in a number of documents.91 The Edinburgh Decision, adopted by the European Council with a view to clarifying the Treaty of Maastricht, affirms that ‘[t]he question whether an individual possesses the nationality of a Member State will be settled solely 89  See Gyulai, G., ‘Statelessness in the EU Framework for International protection’, 14 European Journal of Migration and Law (2012) 284; Molnar, T., ‘Stateless Persons under International Law and EU Law: a Comparative Analysis Concerning their Legal Status, with Particular Attention to the Added Value of the EU Legal Order’, 51 Acta Juridica Hungarica (2010) 304, and Molnar, T., ‘Moving Statelessness Forward on the International Agenda’, 19 Tilburg Law Review (2014) 198. 90 According to Article 8(1) of the Treaty Establishing the European Community, as amended by the Treaty of Amsterdam of 1997, ‘Citizenship of the Union shall complement and not replace national citizenship’. See for commentary on the change of wording Nic Shuibhne, N., ‘EU Citizenship After Lisbon’, in D. Ashiagbor, N. Countouris, I. Lianos (eds), The European Union After the Treaty of Lisbon (Cambridge, Cambridge University Press, 2012), p. 139. 91 Edinburgh Decision of 1992, OJ 1992, C 348, p. 1; Declaration No. 2 on Nationality of a Member State, annexed to the Treaty on European Union, (OJ 1992 C 191, p. 98). European Journal of Migration and Law 19 (2017) 101–135