Parliament has told Theresa May that she cannot lead the UK into a no-deal Brexit. Jean-Claude Juncker, the European commission president, has confirmed that Brussels will not kick a member state out of the European Union. Friday 29 March came and went. Here are the new possible dates of departure:

12 April

An exit from the EU without a negotiated deal at 11pm BST on 12 April remains the legal default. The EU could decide that it has had enough, and that the conditions set for an extension have not been met. Downing Street could reject a lengthy extension. The cabinet is yet to approve a delay to Brexit beyond 22 May, the Brexit secretary, Stephen Barclay, told a Commons committee this week.

7 May

The EU might be tempted to open up a little breathing space between the summit on 10 April and a no-deal crash-out. The French president, Emmanuel Macron, proposed an unconditional extension at the last summit of leaders up to 7 May, on the eve of the French Fête de la Victoire bank holiday, providing a buffer to the economic shock. The EU is also staging a summit in the Romanian city of Sibiu on 9 May to debate the post-Brexit future of the bloc, so it would be best to have the UK out by then.

22 May

If the Commons approves the withdrawal agreement, with or without alterations to the political declaration to win over those seeking a closer relationship with the EU, Britain could still leave with a deal on 22 May, on the eve of the European elections. It would then be in a transition period of 21 months, or longer if an extension of that is required, during which negotiations over the future relationship could start in earnest.

30 June

Theresa May had gone into the last summit seeking an extension until 30 June in the event that she was able to convince the Commons to approve the withdrawal agreement. This would have provided plenty of time to get all the other legislation needed through parliament. Some EU legal advice had suggested that such a date, while not without its problems, would not require the UK to hold elections as the European parliament will not convene until 2 July. But the leaders were not willing to take the risk of having a member state that did not have MEPs. What if the UK suddenly revoked article 50 between 22 May – when elections should have been held – and 2 July? The EU’s institutions would be paralysed. It is highly unlikely, but could the prime minister, after cross-party talks, now convince the EU27 that she has a clear way of getting the withdrawal agreement through and that an extension to 30 June without elections is doable? No, probably not.

31 December

If the withdrawal agreement is not approved before 12 April, the EU will ask Theresa May what she is planning to do. In the event of a general election, an extension to the end of the year might suffice. Certainly the EU believes that this would be the minimum amount of time that would be granted to ensure it was not being unduly disturbed again in the autumn as it is deciding top jobs and policy priorities.

31 March 2020

If Theresa May had asked for the option of a long extension at the last leaders’ summit, the EU had pencilled in 31 March 2020 as the end date. The UK’s first day outside the bloc would fall on April Fools’ Day. This would be long enough for the UK to pass the necessary legislation for a second referendum. And for Brussels it would be just short enough to prevent the UK from meddling in the long-term EU planning on such things as the budget. The discussions are unlikely to be well developed by then.

31 December 2020

This is the 21-month extension that some in Brussels have pushed as a way to ensure that the current crop of British politicians has plenty of time to disappear. But if the UK still wants to leave, there are serious concerns that they could cause trouble within the club. It is expected that the prime minister will have to undertake in the event of any long extension to not use the UK’s voting weight to block key decisions. But such a long extension might be ammunition for Eurosceptic parties who could argue that Britain was being trapped.

TBD

La guillotine: under this approach the UK would be given a nominal date of departure of 31 March 2020 but be allowed to leave as soon as the withdrawal agreement was approved and ratified in Westminster. It offers the EU little certainty about when it will have rid of the UK. It could mean British MEPs being elected, and then sitting for only a few months, before leaving again. The EU27 would be likely to hold elections for MEPs to replace the British ones. And they would wait it out on the sidelines until the eventual departure.

• This article was amended on 5 April 2019 to change 11pm GMT to 11pm BST.



