Citizenship is usually conceptualized as a unitary and exclusive relationship between an individual and a sovereign state; yet the European Union (EU) has developed the most advanced form of contemporary supranational citizenship. Citizenship of the European Union guarantees EU citizens and most members of their families the right to move, live, and work across the territory of the EU. It also guarantees the right to vote in local and European elections in the member state of residence, the right to consular protection outside the EU when the member state of nationality is not represented, the right to access documents or petition Parliament or the Ombudsman in any of the official languages, and the right to be treated free from nationality-based discrimination. Though on the political agenda since the postwar origins of European integration, EU citizenship was not formalized into EU law until the Maastricht Treaty. Since then, the Court of Justice of the European Union (CJEU) has declared that “EU Citizenship is destined to be the fundamental status of nationals of the Member States” and there are ongoing discussions about the relationship between EU and member state citizenship. In terms of identity, increasing numbers of Europeans see themselves as citizens of the EU, and questions of citizenship are at the heart of debates about the nature of European integration.
