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.

This is disputed by…/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’.


Published by

Professor Simon Baughen

Professor Simon Baughen was appointed as Professor of Shipping Law in September 2013 (previously Reader at the University of Bristol Law School). Simon Baughen studied law at Oxford and practised in maritime law for several years before joining academia. His research interests lie mainly in the field of shipping law, but also include the law of trusts and the environmental law implications of the activities of multinational corporations in the developing world. Simon's book on Shipping Law, has run to seven editions (soon to be eight) and is already well-known to academics and students alike as by far the most learned and approachable work on the subject. Furthermore, he is now the author of the very well-established practitioner's work Summerskill on Laytime. He has an extensive list of publications to his name, including International Trade and the Protection of the Environment, and Human Rights and Corporate Wrongs - Closing the Governance Gap. He has also written and taught extensively on commercial law, trusts and environmental law. Simon is a member of the Institute of International Shipping and Trade Law, a University Research Centre within the School of Law, and he currently teaches at Swansea on the LLM in:Carriage of Goods by Sea, Land and Air; Charterparties Law and Practice; International Corporate Governance.

2 thoughts on “The backstop and the 1969 Vienna Convention on the Law of Treaties.”

  1. 1. The VCLT of 69 applies between states. The EU is not a state.
    2. The VCLTIO of 86 applies as between states and international organisations and so, if anything, that would be the relevant instrument.
    3. The EU is party to neither in any event.
    4. Accordingly neither VCLT nor the VCLTIO are applicable directly.
    5. Having said that, in large part the VCLT represents customary international law and indeed the ECJ and ICJ has often said so and points 1 to 4 above are just being picky. Having said that, Article 4 of the WA talks about the application of Union Law and Article 4(1) about direct effect etc. It is not safe to assume that customary international law is coextensive or applicable.
    6. What I find far more fundamentally flawed, however, is the idea of “fundamental change of circumstances” or “material breach” as described taking place. In the former case, the ICJ takes about “radical transformation of the extent of the obligations imposed on it…..”Fisheries Jurisdiction Case UK v Iceland 1973 Rep. 3 in addition to the VCLT criteria, which are customary international law and non-exhaustive conditions.
    7. As to “material breach”, “max fac” or similar has been argued for 2 years now and has not been accepted as feasible. I do not see how it become an obligation of the EU and 27 member states to accept it in 2 years from now.
    8. For there to be a “material breach”, it has to be such as to violate an essential provision necessary to the attainment of the object and purpose of the treaty. The concept of “object and purpose” of a treaty is extremely difficult, but nevertheless I cannot see how a refusal to accept “max fac” could be any such thing given that it is perfectly possible for NI and Ireland to be a single customs union.
    9. This is particularly so when the stumbling block to accepting anything in relation to Northern Ireland is another treaty whose object and purpose is far more obvious….
    10. The only legal comfort I can see is Article 5 of the WA, which contains a general requirement of good faith and “best endeavours” in the Protocol is fairly indicative of what the parties ought to be doing.

  2. Point 7. Max fac doesn’t exist at the moment which is why,understandably, it has been rejected. If it does become technically feasible, in two, three, four, five years time I think that would alter things and I suspect the EU would be quite happy to terminate the backstop. As pointed out in paras 20-21 of the Attorney General’s advice, there are certain advantages to N.Ireland in the backstop which the EU, and the Republic of Ireland, would not want to see continuing indefinitely.

    Point 8. “it is perfectly possible for NI and Ireland to be a customs union”. The DUP might have something to say about that.

Leave a Reply