18 March 2019

Last week, Parliament overwhelmingly voted in favour of seeking an extension to Article 50. Whether or not there is a third meaningful vote this week, and regardless of the result, the Prime Minister will seek an extension at the European Council summit on Thursday; a short one if the deal has passed, but a longer one if it has not. Open Europe have previously examined the positions of the EU27 here.

If the EU27 and the UK agree on an extension, then the UK will remain a member state beyond the current deadline of the 29th March. However, this exit date is also written into UK domestic law, in the EU (Withdrawal) Act 2018. Amending this date in the event of extension would not require primary legislation; there is a provision in the Withdrawal Act for a minister to amend the exit date by moving a Statutory Instrument (SI). The Prime Minister’s written statement on Friday confirmed that this would be subject to the affirmative procedure, meaning it would need to be agreed by (non-amendable) votes in both Houses of Parliament.

If an extension is granted by the EU27, No Deal on the 29th is no longer the “legal default” – whatever the domestic legal situation

Some have argued that even if extension is granted by the EU27, a No Deal Brexit remains the “legal default” unless the exit date in domestic law is also amended. As a result, they argue, either the Commons or the Lords could veto the extension agreed with the EU. Senior Eurosceptic MP Bill Cash, for example, argued in Parliament last week that the date enshrined in the Withdrawal Act is “the law of the land,” and “precludes” any extension of time. Christopher Howarth, a researcher for the European Research Group (ERG) of Conservative MPs, argues in BrexitCentral that to prevent No Deal on the 29th, “Parliament would have to vote to accept the specific date and change the ‘exit date’ in the [EU Withdrawal Act].” And an explainer published in today’s Daily Mail argues, “Once a new date is agreed, the European Union (Withdrawal) Act 2018 has to be amended… if there is no political agreement on changing the date at the EU Council or Parliament rejects the SI, [No Deal] Brexit will still happen as the legal default.”

However, the reality is that once an extension has been agreed and signed off by the EU27, that decision is binding in international law. The UK would legally remain an EU member until the new exit date (unless the Withdrawal Agreement was fully ratified before that). It is EU law, not domestic law, that creates the 29th March legal “cliff-edge.” A failure to amend the exit date in domestic law would not lead to No Deal. Unlike the Withdrawal Agreement itself, the decision to extend does not need to be “ratified” domestically in the UK to have legal effect.

This is not to say that the Government does not need to pass the SI to change the exit date in domestic law. Failing to ensure domestic law was in line with international law would create quite a messy legal situation and a risk of litigation from Brexiteers, as there would technically be no domestic legal basis for continued EU membership. However, whilst this would be undesirable for the Government, it would not be the same as a No Deal Brexit. Once extension is granted by the EU27, No Deal on the 29th March becomes legally impossible.

In any case, it is politically very unlikely that this Parliament – which voted 412-202 in favour of an Article 50 extension last week – would attempt to hold up legislation aimed at changing the UK’s exit date in domestic law. In this context, passing the relevant SIs should be a formality.

This week’s European Council summit is not the “last chance” to agree an extension

Although the decision on extension is likely to be thrashed out at this week’s European Council summit on 21-22 March, a failure by the EU27 to sign it off at the summit would not necessarily lead to No Deal either. EU27 leaders will need to agree a common position at Council, but the extension itself can be signed off by the EU27 at any point before midnight on the 29th – either by an extraordinary meeting, or by written procedure.