The backstop and the 1969 Vienna Convention on the Law of Treaties.

Two pieces of good news for Prime Minister May yesterday. She survived the ’48 Crash’ which precipitated a vote of confidence in her by Conservative MPs – which she won convincingly. Ouseley J threw out the application for judicial review of the article 50 notification brought by Susan Wilson. However, the problem of the backstop still remains and the Prime Minister is now attempting to secure an amendment to the Draft Withdrawal Agreement from the EU on this issue.

This blog’s attention now turns to the public international law implications of the ‘backstop’ in the Northern Ireland Protocol. Sir Edward Leigh MP is of the view that the 1969 Vienna Convention on the Law of Treaties will enable the UK to terminate the backstop on the ground of a fundamental change of circumstances under article 62.

https://www.edwardleigh.org.uk/news/full-stop-backstop

This is disputed by https://policyexchange.org.uk/wp-content/uploads/…/How-to-Exit-the-Backstop.pdf which states:

“In international law, a fundamental change of circumstances is normally understood as relating to something external to the treaty. Moreover, the party invoking fundamental
change of circumstances must also show that the change “was not foreseen by the parties” (Article 62(1), VCLT). In this case, the possibility of the backstop becoming permanent is already foreseen and is indeed already causing concern. On the other hand, this foresight is also in tension with the stated intention that the Protocol is to apply only temporarily.”

It is possible that if a technically feasible system of maximum facilitation for frictionless border checks comes into existence, the backstop would be terminable without agreement with the EU under this article.

It would also be terminable under Article 60(1) of the VCLT  which provides:
“A material breach of a bilateral treaty by one of the parties entitles the other to invoke the breach as a ground for terminating the treaty or suspending its operation in whole or in part.”
Article 60(3)(b) of the VCLT provides that a material breach consists in “violation of a provision essential to the accomplishment of the object or purpose of the treaty”.  Article 2(1) of the Northern Ireland Protocol to the Draft Withdrawal Agreement provides for parties to use their “best endeavours”  to conclude “an agreement which supersedes this Protocol in whole or in part”. This obligation is fundamental to the object and purpose of the Protocol and a refusal by the EU to accept a maximum facilitation system could be regarded as a ‘material breach’.