Leaving the European Union Without a Deal: The Legal Status of the UK's Financial Obligations Under International Law

Abstract

The author considers the principle in international law of the survival of accrued treaty rights and obligations upon the termination of a treaty, and analyses the precise scope of the exception to that principle set out in the Vienna Convention on the Law of Treaties. The scope of the exception is demonstrated to be narrow (and significantly narrower than the scope attributed to it by the House of Lords European Union Committee). A range of potential grounds on which Article 50 of the Treaty on European Union may fall within the scope of the exception (with the result that a departing EU Member State’s treaty obligations would be deemed to be extinguished under international law at the point of its departure) are considered, but all are ultimately rejected. The author argues that, by analogy with other international treaties, Article 50 TEU is properly characterised as an ‘end date’ provision (namely, a provision which is limited to establishing the date on which the treaty will no longer apply to an inter-State relationship, but which does not operate to determine the legal consequences of a State’s withdrawal for its accrued treaty rights and obligations). As Article 50 TEU fails to address these legal consequences, it falls outside the narrow scope of the Convention’s exception to the principle of survival of accrued treaty rights and obligations; and, accordingly, a Member State’s accrued rights and obligations under the EU Treaties will remain binding and enforceable against it as a matter of international law upon its withdrawal from the EU. The author also considers the legal grounds for, and consequences of, designating Article 50 TEU as part of the internal rules of an international organisation under the Vienna Convention, but finds that these too have no legal or practical impact on the survival of a Member State’s accrued obligations under Article 50 TEU following its withdrawal from the EU.