The aim of this paper is to explore the balance between market freedoms and national regulatory autonomy following the en¬try into force of the Treaty of Lisbon, particularly in the light of the rephrased national identity guarantee under Article 4(2) TEU. The pa¬per will discuss whether the newly established obligation of the Euro¬pean Union to respect the national identities of its Member States has any consequences in the case law of the European Court of Justice. Arguably, defining the proper scope of application of the national iden¬tity guarantee is relevant to the application of EU law, since it disturbs the previously established balance between European and national law. If defined too broadly, it can undermine the uniform application and effectiveness of EU law. If defined too narrowly, it would be de¬void of any useful effect.