Exit day up in the air: understanding the Brexit delay

Christine ONeill, Chairman, Brodies
Christine ONeill, Chairman, Brodies
Promoted by Brodies LLP

For the last two years, 11pm on 29 March 2019 has been expected to be the (precise) moment when the UK’s EU membership would cease.

For the last two years, 11pm on 29 March 2019 has been expected to be the (precise) moment when the UK’s EU membership would cease. The likelihood of that seems to be diminishing now the Prime Minister has formally requested a postponement of the UK’s exit to 30 June, though it remains to be seen how the EU27 will respond: the UK’s request will be considered at today’s EU summit with the prospect of a further, emergency, summit as late as 28 March. 29 March may yet remain the date if the EU27 refuse the extension request and no agreement can be reached on a mutually acceptable alternative.


Article 50 of the Lisbon Treaty is clear. A country that has given notice of its intention to leave the EU stops being a member state (in technical terms the EU treaties ‘cease to apply’ to it) when a withdrawal agreement with the EU comes into force or, absent an agreement, 2 years after the date of the original notice. Exit is automatic unless all the member states agree, unanimously, to extend the negotiating period. While an extension would set a new ‘fallback’ date for Brexit, it could still take place sooner if a finalised withdrawal agreement provided for that.


Failure to agree an extension would leave three options. The first is exit without any deal at all (or ‘hard Brexit’) on 29 March. The second is a last minute further attempt to secure the Commons’ approval of the existing withdrawal agreement. Even if that attempt were to succeed it is now widely acknowledged that a short extension would be needed to legislate properly for exit. The last option would be an unconditional withdrawal of the Article 50 notice – abandoning Brexit – which the European Court of Justice confirmed was possible earlier in the year.
Several commentators have suggested that, even if the EU agrees to an extension, we might nevertheless ‘accidentally’ leave the EU on 29 March because British laws still provide for exit on that date. In particular, the European Union Withdrawal Act 2018 uses the concept of ‘exit day’ to trigger various changes to UK law, including repealing the European Communities Act 1972 (described as the ‘conduit’ through which European law flows into the UK). ‘Exit day’ is currently expressly defined as 29 March.


For a range of reasons this shouldn’t prevent continued EU membership if an extension is agreed. First, the Withdrawal Act would not change the EU’s perspective on our membership: as a matter of EU law we would remain bound by the treaties. Second, the date of ‘exit day’ can be changed by the Government using secondary legislation. While Parliament would have to approve any change, and there might be some resistance to that, the Commons’ recent vote against a no-deal exit means it would likely be accepted. Finally, while section 1 of the Withdrawal Act would repeal the 1972 Act on exit day – blocking the conduit – that section has not itself been brought into force by the Government. The 1972 Act would therefore remain the law, and would ‘trump’ anything else the Withdrawal Act says.

Christine O’Neill is the Chairman at Brodies LLP