The Concept of Constitutional Identity as a Substantive Expression of the Principle of Subsidiarity.

The introduction of the subsidiarity principle by the Maastricht Treaty was intended to strike a balance between the Member States and the supranational level in terms of non-exclusive competences. However, the principle of subsidiarity in the current EU structure is Janus-faced: although it was theoretically included in the founding treaty to protect the lower levels, its modus operandi is actually aimed at demonstrating the supranational level’s capacity to act. Perhaps this is why the enshrinement of the subsidiarity principle in the Treaty has not lived up to expectations, and the relevant Treaty provisions have largely remained dead letters. At the same time, the need represented by the principle of subsidiarity, namely the protection of the autonomy of the Member States, remained present in European integration, which finally emerged in the concept of constitutional identity, linked to the redefined identity clause after the Lisbon Treaty. In this sense, the identity clause in Article 4(2) TEU has become the legal device or standard that is able to transfer the constitutional needs of the Member States to the level of EU law and provide the possibility for their recognition at EU level. For this to work, a cooperative approach by national constitutional courts seems essential. [ABSTRACT FROM AUTHOR]