Embattled British Prime Minister Theresa May will rely on the latest pledge from the EU on the Irish backstop, as she scrambles to save her Brexit deal.
Mrs May is now partly relying on assurances from the EU on the backstop to persuade more MPs to support her plan.
European leaders Jean-Claude Juncker and Donald Tusk will issue a letter to the British Government, which is expected to be made public today.
It will set out a series reassurances on the backstop – which is the fallback plan if no trade deal is struck after the UK leaves the bloc.
The UK will also commit to doing everything it can to avoid the backstop taking effect. However there will be no renegotiation of the backstop at this stage.
Mrs May is expected to set out details of the reassurances from the EU in a statement to the House of Commons this afternoon.
She will reiterate that the mechanism is not designed to separate Northern Ireland from the rest of the UK – something that is vital in order to appease the DUP who are propping up the Conservatives in Government.
MPs are to vote on Mrs May’s deal tomorrow night, with No 10 braced for a defeat by an unprecedented majority of more than 200.
Separately, Pro-EU MPs will today raise the stakes in the battle over Brexit by publishing draft legislation to force a second referendum that could reverse the result of the 2016 vote.
A cross-party group of MPs, including Dominic Grieve, the former Conservative attorney general, wants Theresa May to give Parliament a greater say in deciding how Britain leaves the European Union.
It comes after reports emerged at the weekend of a planned “coup” by unnamed senior MPs to grab control of the parliamentary timetable by allowing backbenchers’ legislation to take precedence over the government’s.
The cross-party draft legislation published today by Mr Grieve, the Liberal Democrat leader Vince Cable and Lord Lisvane, the former clerk of the House of Commons, proposes another referendum in which voters would be given a choice between Mrs May’s deal or staying in the EU.
The draft law could in theory be tabled as early as Monday next week, if Mrs May loses tomorrow and she has to come back to the Commons with a new plan for delivering Brexit. It will require the Speaker, John Bercow, to suspend centuries-old rules and make it easier for MPs to table laws that can be passed.
Mrs May has warned MPs they risk “undermining the public’s faith in democracy” if they reject her Brexit deal in the looming vote.
She accused some MPs of “playing political games” in the marathon Brexit debate. She said MPs should respect the results of the 2016 referendum in which 52pc of voters backed leaving the EU.
The prime minister said parliament failing to give her deal the necessary backing “would be a catastrophic and unforgivable breach of trust in our democracy”.
She used a newspaper article to issue a last-ditch plea to members of her own Conservative Party, the 10 DUP MPs propping up her minority government, and some pro-EU people on the Labour benches.
“So my message to Parliament this weekend is simple: it is time to forget the games and do what is right for our country,” she wrote.
Observers say Mrs May has very little chance of succeeding in tomorrow’s vote. Two procedural vote losses last week have also limited her room for manoeuvre, including a demand that she produce alternative plans within three sitting days of any vote loss.
Labour leader Jeremy Corbyn’s priority is to force a general election. He said he will propose a motion of no confidence in the government if it loses tomorrow’s vote.
Speaking on the BBC’s ‘Andrew Marr Show’ yesterday, he said: “We will table a motion of no confidence in the government at a time of our choosing, but it’s going to be soon, don’t worry about it.”
Brexit Minister Steve Barclay has warned of the growing risk that the UK parliament could block Brexit altogether.
Mrs May’s office said it was “extremely concerned” about reports in one Sunday newspaper that some MPs would try to seize control of Brexit negotiations if tomorrow’s vote is lost. The ‘Sunday Times’ reported that senior MPs intend to try to change the rules of the House of Commons so they can wrest control of the law-making agenda from the government.
Mrs May faces widespread opposition to the deal, primarily on the issue of the backstop to avoid a hard Border between Northern Ireland and the Republic. Many MPs fear it could leave Britain tied to the EU indefinitely.
Reports from Westminster suggest more than 200 of the 650 MPs back the deal, far short of the number needed for it to pass. About 100 MPs support a no-deal Brexit, while other groups favour either a “soft Brexit” keeping the UK close to the EU, or a second referendum.