The Legal and Political Process for Agreeing the Future Relations between the EU and the UK and Any Transitional Agreement

Tobias Lock

Research output: Book/ReportCommissioned report


When negotiating the UK’s withdrawal from the EU and a future relationship with it, the European Union is acting under considerable legal and political constraints. The legal constraints stem from the fact that the EU only has limited powers and – without including the Member States as parties – can only tie itself to an agreement that falls within its competences. There are additional political constraints on the EU’s negotiator, who is confined by the negotiating guidelines set by the European Council and by the negotiating directives formulated by the Council. Furthermore, the ratification of both the withdrawal agreement and an agreement about the future relationship requires the consent of the European Parliament.
Additional pressures are caused by the tight time-frame of two years for the conclusion of a withdrawal agreement, which will end on 29 March 2019. If no withdrawal agreement is concluded, the UK will leave the EU without a deal on that day, unless the two year period is extended unanimously. But even if a withdrawal agreement is concluded in time, there may not be enough time to also come to a final agreement – including ratification – over the future relationship in terms of trade, security, and other forms of cooperation. This makes a transition period, which will see the UK outside the EU, but still partake in most EU policies including the single market and customs union, a practical necessity.
A withdrawal agreement based on Article 50 TEU can, in all likelihood, also include transitional arrangements provided that these arrangements are truly transitional and do not become permanent. A transitional arrangement will – as far as possible – aim to replicate the UK’s current status in the EU while allowing the UK to formally leave on 29 March 2019. The UK will probably have to agree to be bound by the full EU acquis and the EU’s enforcement mechanisms including oversight by the Court of Justice, but will no longer have a role in the EU’s decision-making processes.
As far as the future relationship is concerned, there are a number of avenues the EU and the UK could pursue: a free trade agreement (the ‘Canada model’), an association agreement (the ‘Ukraine model’); a set of bilateral agreements replicating much of the single market (the ‘Swiss model’); or membership of the European Economic Area (the ‘Norway model’), but it should be noted the only pre-negotiated route is the Norway models. All other models are unlikely to be replicated in their exact details due to the unique circumstances and dynamics of each treaty negotiation process. It should further be noted that EU-UK relationship is also envisaged to cover fields other than trade, in particular security cooperation. While the EU has far-reaching external competences covering most if not all of these matters, it is likely that the EU Member States will insist on the future relationship agreement being concluded as a mixed agreement. This will require ratification of the agreement not only by the EU and the UK, but by all the EU-27 as well.
Original languageEnglish
PublisherScottish Parliament
Commissioning bodyScottish Parliament
Number of pages40
Publication statusPublished - 20 Dec 2017


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