Brexit: What are MPs voting on today and what happens if Theresa May loses?

Everything you need to know about another crucial Brexit vote

Having twice failed to get her Brexit deal approved by MPs, Theresa May is now trying a different approach.

MPs will vote again on the plan on Friday, but this vote will be significantly different to the first two, as the prime minister tries one last throw of the dice to secure backing for her deal.

The House of Commons was not initially due to be sitting on Friday – the day that Britain was supposed to leave the EU – but MPs have been told to stay in Westminster so the government can hold this crunch vote.

The vote will take place at around 2.30pm.

Is this another “meaningful vote”?

No. The term “meaningful vote“ was coined to describe a Commons vote on both parts of the deal that Theresa May has negotiated with the EU: the Withdrawal Agreement and the Political Declaration. The two documents are very different. The Withdrawal Agreement is a legally-binding treaty laying out how the UK will leave the EU, while the Political Declaration is not binding and instead is simply a statement of aims regarding the future relationship between the UK and EU after Brexit.

British law, in the form of the EU Withdrawal Act (2018), states that for the UK to ratify the exit deal with the EU, both the Withdrawal Agreement and the Political Declaration must have been approved by the House of Commons via a vote on a motion tabled by a government minister. This is what has become known as the meaningful vote.

On Friday, MPs will vote only on the Withdrawal Agreement, not the two parts of the deal together – hence why this is not a third meaningful vote.

Why is the government holding a vote on only one part of the deal?

The previous two votes on Ms May’s exit plan have seen both parts of her deal voted on together. The prime minister’s decision to put only the Withdrawal Agreement back in front of the Commons is a direct result of a European Council ruling last week. The Council, which is made up of EU heads of state, said it would be willing to delay Brexit to 22 May only if parliament approved the Withdrawal Agreement this week. Crucially, it did not say the Political Declaration also had to be signed off.

The government is desperate to keep the 22 May date on the table because the most likely alternative is a lengthy delay to Brexit.

That is why, in a last-ditch bid to meet the conditions set out by the EU, the government is holding a vote only on the Withdrawal Agreement.

The Political Declaration will also need to be approved before Britain leaves the EU, but ministers are gambling that they can cross that bridge at a later date.

The other reason for splitting the vote is to circumvent a ruling by John Bercow, the Commons speaker, that the government cannot simply call another vote on its unchanged deal. Deciding to hold a vote only on the Withdrawal Agreement allowed ministers to successfully argue to Mr Bercow that this was substantially different to the first two votes.

Is the Withdrawal Agreement likely to pass?

No. Despite extensive lobbying and fresh concessions from government ministers, the DUP has said it will still not vote for the deal. At least 20 Conservative Eurosceptics are also still vehemently opposed to the backstop part of the Withdrawal Agreement, which spells out how the Northern Ireland border will be kept open if no trade deal is agreed.

Labour will also vote against the proposed exit deal. While its main criticism is of the Political Declaration rather than the Withdrawal Agreement, the party says the two documents cannot be divided and so it will order its MPs to vote against the government.

A few Labour rebels who represent Leave-voting areas might back the plan, but there are not expected to be enough to outnumber the DUP and Tory Brexiteers.

What happens if Ms May wins?

If the Withdrawal Agreement unexpectedly passes the Commons on Friday, the prime minister will have met the key deadline laid out by the European Council. She would then have until 22 May to secure parliament’s backing for the second part of the deal: the Political Declaration.

This is no easy task, given parliament is deeply divided about how closely the UK should remain tied to the EU after Brexit. However, the strongest opposition from her own party and her governing partners in the DUP relates to the backstop, which is in the Withdrawal Agreement. Having the more contentious part of the deal approved would therefore be a major boost for the prime minister. The fact that the Political Declaration is not legally-binding means some MPs might be willing to vote for it in the knowledge that its contents could be amended by a new prime minister at a later date.

Securing MPs’ backing for the Withdrawal Agreement would also allow the government to introduce the Withdrawal Act Bill, which implements the provisions of the agreement. This would edge the UK closer towards leaving the EU by the new deadline 22 May. It is thought that the government could seek to have the Political Declaration approved during the votes on this bill.

Ms May’s own future also rests on what happens on Friday. She announced this week that she will step down if her Brexit deal is approved by parliament. A Commons vote in favour of the Withdrawal Agreement would bring that much closer.

What happens if she loses?

Not a great deal would change.

The European Council ruling says that, if the Withdrawal Agreement is not approved this week, the UK will have until the 12 April to either leave with no deal or put forward an alternative plan.

MPs are almost certain to block a no-deal exit, so the most likely alternative is for the government to request a long delay to Brexit so parliament can work out what kind of deal it would be able to support. An increasing number of MPs think that only a general election will break the deadlock.

The group of senior backbenchers that seized control of the Commons agenda on Wednesday to hold a series of “indicative votes” on Brexit will do so again on Monday. They hope that this will narrow down the eight options MPs voted on this week and that it will become clearer what type of Brexit parliament might be willing to support.

This could give Ms May the basis of a new proposal to take to the EU. But she has made clear that she is not willing to delay Brexit any further – raising the prospect of her resigning and allowing a new prime minister to reopen talks with Brussels.

What does it mean for a Final Say referendum?

It does not have a direct impact, but supporters of a fresh Brexit referendum believe it is most likely to happen once all of the other options have been exhausted. If the Withdrawal Agreement passes, that would appear less likely to happen.

If MPs again reject the Withdrawal Agreement, however, the possibility of another referendum will remain on the table and will likely be voted on against in Monday’s second round of indicative votes.