Following the Prime Minister’s speech in Florence on 22 September 2017, there is growing, albeit not universal, political consensus around the notion of a transitional — or ‘implementation’ — period. The intention is that such a period would bridge the gap between the UK’s formal departure from the European Union at the end of March 2019 and the conclusion and ratification of an agreement concerning a new, permanent relationship between the EU and the UK.

The prospect of such a transitional period raises obvious political issues. But it also raises important, and difficult, legal questions. At the EU level, questions arise about what legal vehicles might be available for the purpose of navigating the uncharted terrain in which both the EU and the UK presently find themselves. Meanwhile, at the domestic level, there are questions about how a transitional period might be legally accommodated — and, in particular, about whether the European Union (Withdrawal) Bill, currently making its way through the House of Commons, makes adequate provision for transition as distinct from full exit. These questions are examined in a briefing paper published today by the Cambridge Faculty of Law’s Centre for European Legal Studies and Centre for Public Law. In the paper, Kenneth Armstrong, John Bell, Paul Daly and I consider the legal means by which a transitional period might be delivered at both the EU and domestic levels.

Consideration of these legal issues raises a prior question about what ‘transition’ is intended to mean in this context, and what it is intended to achieve. Once that question is confronted, it becomes far from clear whether ‘transition’ — or an ‘implementation period’ — is really anything more than a euphemism for the purchasing of breathing space, as the still-unfolding complexities of Brexit are laid bare and grappled with by both the UK and the EU. If, then, the purpose of transition is conceived in this way, it is difficult to see why it should not amount to a perpetuation of the status quo, rather than some form of temporary, bespoke arrangement.

Of course, the politics and the presentation of the matters are another issue entirely, and there is undoubtedly a strong political imperative in favour of designing transition in a way that looks like something other than simply kicking the can down the road. But as a matter of law, the more significantly transition differs from the status quo, the more complex its accommodation, both in EU and domestic legal terms, is liable to become. It will therefore be necessary for the Government to decide to what extent it is willing to sacrifice legal simplicity, stability and continuity in the interests of securing a transitional arrangement that can be sold as form of Brexit in and of itself, rather than as a mere precursor to — and so a deferral of — the UK’s formal departure from the EU. Against that background, we conclude that while the political obstacles to extending the two-year negotiation period set by Article 50 of the Treaty on European Union are doubtless very substantial, such an approach — coupled with the deferral of ‘exit day’ for the purposes of the European Union (Withdrawal) Bill — would represent the cleanest and most straightforward legal solution.

A copy of ‘Implementing Transition: How Would it Work?’ can be downloaded here.