The past, present, and future of Union membership: a constitutional analysis

This paper reflects on the concept of ‘Union membership’ and on the status of ‘Member State’ of the European Union. It concentrates on what can be defined as ‘EU membership law’, i.e. on the legal framework of membership contained in the Union treaties. The paper first analyzes how the meaning and consequences of membership have evolved over time: broadly speaking, the scope of membership requirements has greatly expanded, even well beyond the legislative competences of the Union. It then discusses the current Treaty framework, identifying and analyzing the key provisions on membership status, procedures (accession and enlargement), and obligations. In the final part, it explores a set on current challenges that are shaping the concept on membership, from Brexit to the constitutional crises of Hungary and Poland, and reflects on whether there is a need to identify a ‘core’ or essence of membership that should not be diluted regardless of the directions the EU will take.