Brexit and Acquired Rights

As a hybrid provision, the much-discussed withdrawal provision in Article 50 of the TEU is part of European Union law yet also anchored in public international law. Due to this anchoring of EU law, the UK's withdrawal raises important questions of public international law that are the focus of this essay. First, this essay examines the relationship between the specialized withdrawal right in Article 50 of the TEU and the customary international law on withdrawal from treaties in Article 70 of the Vienna Convention on the Law of Treaties (“VCLT”), and explores its implications for the UK's obligations vis-à-vis the EU and its member states. Second, it looks at how Brexit affects the acquired rights of third parties to the EU treaties, namely those of citizens of the other 27 EU member states—an issue that brings Brexit's most critical practical challenges into sharp focus