The prime minister will hold talks with top EU officials, before leaders of all 27 EU member states convene on Sunday. The one-off summit was called to formally sign off the Brexit draft agreement. But it’s not likely to be smooth sailing for Theresa May this weekend.
Spanish officials have said they won’t attend the summit unless the spat over Gibraltar is resolved.
There won’t be a formal vote this weekend, but it is expected a vote will soon follow once the EU Council has reached a consensus to sign off the deal.
Ahead of the crunch summit, Theresa May will meet with EU Commission President Jean-Claude Juncker, and EU Council President Donald Tusk.
READ MORE: If Theresa May loses the vote in Commons – what’s next for Brexit?
What is the timeline?
The exact time of the meeting with Jean-Claude Juncker has not been made public, but it is expected in the afternoon, as Mr Juncker has a working dinner with the Italian prime minister in the books.
Donald Tusks’s public calendar shows his meeting with Theresa May is penned in for 7.15pm on Saturday night.
And then on Sunday at 8.30am local time (7.30am GMT), the summit kicks off.
At 9.30am, there will be an “exchange of views with the President of the European Parliament,” Antonio Tajani.
At 10am, a working session of the council begins, in relation to Article 50 which will remove the UK from the EU.
At 11am it’s Theresa May’s moment to talk the 27 leaders of the EU member states to approve her deal.
And at midday (11am GMT), a press conference will be held by Donald Tusk and Jean-Claude Juncker.
By then, we should have a better idea of that will happen next: if Spain doesn’t attend it could put a spanner in the works.
The EU Council doesn’t always require all member states to unanimously approve a decision, but they do on “sensitive” topics, such as this one.
And even if Spain comes around, Theresa May will still have to present the deal to MPs back home to vote, and as we’ve seen lately, a lot of them are already declaring they will veto it.
What will the EU need to approve?
The member states will be asked to approve two documents:
1) The political declaration, which sets out what the UK and EU’s relationship may be like after Brexit – outlining how things like UK-EU trade and security will work.
2) The EU withdrawal agreement: a 585-page, legally-binding document setting out the terms of the UK’s exit from the EU. It covers the UK’s £39bn “divorce bill”, citizens’ rights and the thorny issue of the Northern Ireland “backstop” – a way to keep the border with the Republic of Ireland open, if trade talks stall.