Citizenship of the European Union
In accordance with the 1992 Maastricht Treaty on European Union (Article 9) and the 2009 Treaty on the Functioning of the European Union (Article 20). Anyone who holds the nationality of a Member State is a citizen of the Union. Citizenship of the Union is additional to and does not replace national citizenship. Citizenship of the Union includes a number of additional rights and obligations
In Case C-135/08 Janko Rottman v Freistaat Bayern, Advocate General of the CJEU Poiares Maduro explained this difference (paragraph 23 of his opinion):
“These two concepts are both inherently related and autonomous from each other. Citizenship of the Union presupposes the existence of citizenship of a Member State, but at the same time constitutes a legal and political concept distinct from the concept of citizenship of a Member State. Citizenship of a Member State not only opens up access to rights conferred by Community law, but also makes us citizens of the Union. European citizenship is not only a set of rights which, as such, could be granted even to persons who do not. It presupposes the existence of political ties between European citizens, although it is not about belonging to one nation. […] It is based on their mutual commitment to open their political communities to other European citizens and to establish a new form of civic and political solidarity on a European scale.
It does not require the existence of a nation, but is based on the existence of a European political space from which derive rights and obligations. Since European citizenship does not presuppose the existence of a European nation, it is conceptually divorced from the citizenship of a Member State. As one author pointed out, the decisively innovative nature of the concept of European citizenship lies in the fact that “the Union belongs to and is made up of citizens who by definition have different nationalities”. On the contrary, by stating that the possession of the nationality of a Member State is a condition for the possession of European citizenship, the Member States wished to point out that this new form of citizenship does not undermine our original belonging to national political communities. Thus, the link with the nationality of the individual Member States constitutes recognition of the fact that there can be (and does exist) a nationality which is not determined by the nationality of any country.
This is the unique nature of EU citizenship - it strengthens the ties that bind us to our countries (because we are European citizens precisely because we are citizens of our countries), and at the same time emancipates us from these countries (because we are citizens above our countries). Access to European citizenship is gained through the citizenship of a Member State, which is governed by national law but, like any form of citizenship, forms the basis of a new political space which gives rise to rights and obligations laid down by Community law that do not depend on the state. [...] For this very reason, while it is true that the citizenship of a Member State is a condition for access to citizenship of the Union, it is also true that the totality of the rights and obligations related to the latter may not be unduly restricted on account of the former "
Source:
https://www.europarl.europa.eu/factsheets/pl/sheet/145/obywatele-unii-europejskiej-i-ich-prawa
