We have explained in some detail the procedure and timetable that applies now that UK has given notice of withdrawal under Article 50 of the Treaty on European Union.
There is, however, an alternative possibility which has sometimes been raised which we wish to comment on, although it has been rather superseded by events. The alternative option posited in certain quarters was that the UK should give a shorter period of notice, and accompany this with a repeal of the European Communities Act 1972 at the end of that shorter notice period.
Withdrawal and the Vienna Convention
The legal argument upon which this suggestion rests is that according to the customary international law of treaties, which is codified in the 1969 Vienna Convention on the Law of Treaties, the UK or any other Member State is entitled to withdraw from the EU on reasonable notice, and that reasonable notice could be a shorter period than the two years under Article 50.
The problem with this argument is that the implied right of a State to withdraw from a treaty on notice, which is set out in Article 56 of the Vienna Convention, applies only to treaties which contain no provision regarding termination. That Article reads, in full:
Denunciation of or withdrawal from a treaty containing no provision regarding termination, denunciation or withdrawal
1. A treaty which contains no provision regarding its termination and which does not provide for denunciation or withdrawal is not subject to denunciation or withdrawal unless:
(a) it is established that the parties intended to admit the possibility of denunciation or withdrawal; or (b) a right of denunciation or withdrawal may be implied by the nature of the treaty.
2. A party shall give not less than twelve months’ notice of its intention to denounce or withdraw from a treaty under paragraph 1.
Article 50 was introduced into the Treaty on European Union by the Lisbon Treaty which came into force in 2009. Prior to the Lisbon Treaty, there was nothing in the European treaties specifying any right of withdrawal, and so it would have been possible to argue that there was an implied right to withdraw in accordance with Article 56 of the Vienna Convention. In order to do so it would have been necessary under Article 56(1)(a) or (b) quoted above to establish that a right of withdrawal was either intended by the parties or “implied by the nature of the treaty.” This would have given rise to considerable argument, since it was possible to contend (and was contended by some) that no right of withdrawal existed at all.
However, since the introduction of Article 50 into the Treaty on European Union, this is all by the by. The Member States by adopting Article 50 have made it clear, first, that there is a right of withdrawal thus putting that point beyond argument, and secondly that the right of withdrawal is exercisable according to the 2-year notice period laid down in Article 50. Since the Treaty of European Union now contains an explicit clause dealing with withdrawal, there is now simply no possibility of Article 56 of the Vienna Convention applying to the EU Treaties post-Lisbon.
Repealing the 1972 Act
Nor would repealing the European Communities Act 1972 help. It is correct that as a matter of the UK’s internal law, Parliament could repeal the 1972 Act and in doing so bring to an end the enforceability of the EU Treaties and directly applicable EU Regulations in the UK courts. But such an action would be a blatant breach of the international obligations of the UK under the EU treaties. The fact that Parliament under UK internal law has the power to do this would not excuse or justify that breach.
Whether or not they like it as a matter of political preference, other EU Member States recognise that the UK has a clear legal entitlement to withdraw under Article 50 of the Treaty on European Union, and is acting in full conformity with the Treaties having exercised that right. That is the background of our negotiations on a new trade relationship: the UK has consistently complied with its treaty obligations under the EU Treaties in the past, and can be expected to comply with the provisions of a new trade treaty in the future.
If on the other hand, we had disregarded the provisions of Article 50, the other Member States would certainly have regarded that as a blatant breach of the Treaty (and, for the reasons explained above, they would be fully justified in taking that position). Why should they then enter into a new treaty with a State which has exhibited a willingness to blatantly disregard its obligations under the old one?
No practical point
A further question is whether, even assuming these legal difficulties somehow were to disappear, any practical purpose would have been served by giving a shorter notice of withdrawal outside the framework of Article 50.
Following the Brexit decision, there is a very considerable task of revising UK domestic law, and putting in place revised international treaty relationships on trade (and numerous other matters) with third states and with the EU itself. It is not simply a matter of sweeping everything away in one fell swoop, since many areas of policy are now covered either by direct EU law or EU-derived law. We cannot simply sweep away all the changes in our law which have happened since we joined the EEC and revert to the law as it stood in 1972. A detailed review process needs to be undertaken.
It is challenging to complete this process within 2 years, which is why the government is now seeking a further 2-year “transitional” period. If necessary (for example if the negotiations on the withdrawal agreement break down) it is realistically achievable in 2 years, but very difficult to see how it could have been done in a significantly shorter period such as one year.
Back to Guide to Brexit Contents Page