When Do Union Citizens and Their Families Have the Right to Equal Treatment on Grounds of Nationality in EU Law?

Abstract Article 18 TFEU appears to prohibit nationality discrimination throughout the scope of EU law, but the Court of Justice uses various techniques to often deny equal treatment to people who are within that scope. It wants to create a layered regime of rights, which takes account of the degree of integration and participation of Union Citizens and their families, but this ambition is in tension with the apparently simple Article 18 rule. The solution, this article suggests, is to recognize that discrimination itself is a layered concept, allowing for justified distinctions, and so for different treatment of different groups. There is a surprising amount of support for this view in the case law. The article looks at the cases on equal treatment for Union Citizens and their families, including TCN family members, and tries to provide a coherent conceptual and legal frame which explains their results.