In earlier posts (here and here) there was a discussion about the different scenarios that might play out following the UK’s vote to exit the European Union. These and other debates have focused largely on the legal implications for the UK and the European Union and the modalities of their future relationship. Yet the UK’s withdrawal from the Union will also have consequences at the international level, especially for the hundreds of international agreements concluded by EU and the UK with third states and international organizations. In this post I will look at some of the international law issues that arise from the UK’s exit from the European Union. The EU is a unique, perhaps even sui generis, international organization, but it is an international organization nevertheless and withdrawal will necessarily gives rise to questions under public international law. An important question in this regard is the fate of the international treaties to which the EU and the UK are party.
The first point of departure are the rules in the treaty establishing the international organization itself, that is, the EU Treaties. The Vienna Convention on the Law of Treaties (VCLT) establishes that a party may withdraw ‘in conformity with the provisions of the treaty’, which in this case is Article 50 of the Treaty on European Union (TEU). Once this has been invoked, the EU and the UK will negotiate an agreement setting out the arrangements for withdrawal. Some have argued that the UK might be able to ‘bypass’ Article 50 TEU using international law, by invoking the Brexit vote as a ‘fundamental change in circumstances’ according to Article 62(1)(a) VCLT. Such proposals should not be taken seriously. This article of the VCLT was deliberately worded negatively, stating that a fundamental change in circumstances cannot be invoked unless two restrictive conditions are fulfilled. These are: (a) the existence of those circumstances constituted an essential basis of the consent of the parties to be bound by the treaty; and (b) the effect of the change is radically to transform the extent of obligations still to be performed under the treaty. The International Court of Justice has moreover pointed out “the stability of treaty relations requires that the plea of fundamental change of circumstances be applied only in exceptional cases.” (Case concerning the Gabčíkovo-Nagymaros Project (Hungary/Slovakia) (Judgment)  ICJ Rep 7. para. 104) As Professor Kenneth Armstrong argues:
“there is simply no way that the European Court of Justice would permit the autonomous legal order of the European Union and the specific procedural mechanism of Article 50 TEU to bend to international law in this manner.”
While it is possible that avenues other than Article 50 may be used (for instance, to allow a form of ‘associate membership’) the EU Treaties provide a clear provision that covers the exit of a Member. Article 50 is silent, however, for the most part on the important issues that will face the UK, the EU and the many other states with whom they have legal relations. Read the rest of this entry…