Theresa May was facing the fight of her political life last night to persuade Cabinet ministers, MPs and the country to back her Brexit deal.
More than two years after Britain voted to quit the EU, UK and Brussels negotiators finally broke the deadlock to conclude a draft withdrawal agreement. The proposed treaty, more than 500 pages long, could be rubber stamped at a special EU summit in the Belgian capital later this month. But the Prime Minister now needs to win the backing of her Cabinet for the deal at a crunch emergency meeting in Downing Street this afternoon.
Allies of Mrs May said she was arguing passionately that the deal will return control of laws, borders and billions of pounds of taxpayers' money to the UK.
"This is a deal that delivers for the millions of people who voted to leave the EU," the Prime Minister was understood to have told friends last night.
In the opening shots in the mammoth political battle ahead, furious Euro-sceptic Tories yesterday claimed the package will leave Britain tied to Brussels forever.
Former foreign secretary Boris Johnson said: "For the first time in a thousand years, this place, this Parliament, will not have a say over the laws that govern this country. It is a quite incredible state of affairs."
And senior Tory Jacob Rees-Mogg added: "White flags have gone up all over Whitehall. It is a betrayal of the Union."
He said that if leaks about the deal were correct the “Cabinet should reject it”.
“They should vote it down, they should make it clear that the Cabinet will not support it,” he said.
“It is harder to leave the customs union under the proposed backstop than it is currently so we go from being a vassal to being a slave.”
As the effort to win Tory hearts and minds began last night, the Prime Minister held a series of tense one-to-one meetings with Tory Cabinet ministers in Downing Street following concerns several were poised to quit in protest at details of the deal.
EU Exit Secretary Dominic Raab was the first minister to see the Prime Minister. He was followed by Transport Secretary Chris Grayling, Health Secretary Matt Hancock, International Trade Secretary Liam Fox and Commons Leader Andrea Leadsom.
They emerged from Number 10 tight-lipped after each spending around half an hour with the Prime Minister.
Cabinet ministers were also invited to read copies of the draft document in a secure room in the Cabinet Office.
Westminster was plunged into feverish speculation yesterday afternoon as news of a technical deal between the two negotiating teams began to emerge from Brussels.
After several days of talks between officials in Belgian capital that ran into the early hours, officials finally hammered out a potential solution to the row over the future of the Northern Ireland border that had turned into the key stumbling block in the talks.
Sources close to the talks said the break through was finally achieved when the EU back down over contentious details in the plan for a so-called Northern Ireland "backstop" which could have imposed customs checks on goods travelling between Northern Ireland and the rest of the UK.
"The deal contains a UK-wide backstop. After extensive debates, the demands that would have effectively meant customs checks in the Irish Sea have been dropped," said one source close to the UK negotiating team.
Other sources said a "review mechanism" had been agreed to ensure the temporary backstop could not become permanent.
Cabinet ministers met Mrs May at Downing Street for one-to-one talks (Image: REUTERS)
But it was unclear whether the mechanism would satisfy warnings from Eurosceptic Tories that the backstop could lead to the UK being indefinitely tied into a swathe of EU regulations that Parliament will have no say over.
Official confirmation from the Government that the draft agreement had been finalised came at 5pm yesterday when a statement from Downing Street said: "Cabinet will meet at 2pm tomorrow to consider the draft agreement the negotiating teams have reached in Brussels, and to decide on next steps.
"Cabinet Ministers have been invited to read documentation ahead of that meeting."
The draft deal is understood to include a 500-page withdrawal agreement and a four-page political declaration about the UK's future relationship with the EU.
Scottish Secretary David Mundell, one of the first Cabinet ministers to speak out about the deal, gave it a cautious welcome while warning details could prove problematic.
"Obviously members of the Cabinet are going to have the opportunity to look at that in detail this evening and there will be a special Cabinet meeting tomorrow to reflect on what's in that documentation," he said.
"So I'm encouraged, but we need to reflect on that detail and see what's there and hopefully be in a position to take forward a deal.
Tory Chief Whip Julian Smith was confident the Prime Minister will get Commons backing for the deal.
"I am confident that we will get this through Parliament and that we can deliver on what the Prime Minister committed to on delivering Brexit," he said.
"The negotiation team have been working through the night for the last few weeks and we're hopefully on the cusp of beginning to get to the point where we are delivering on Brexit in a really practical way."
But in a sign of the dangerous Commons divisions ahead, MPs in the Democratic Unionist Party, crucial allies to Mrs May's minority Tory government, were understood to be furious about the plans.
DUP deputy leader Nigel Dodds said that the deal as reported would leave Northern Ireland "subject to the rules and laws set in Brussels with no democratic input or any say".
He added: "We object to that on constitutional grounds that our laws would be made in Brussels, not in Westminster or Belfast. That is the fundamental red line."
He warned that the deal could be a “breach of the Prime Minister’s pledges” to the people of Northern Ireland and urged Cabinet ministers to "stand behind the Union".
Former Tory leader Iain Duncan Smith warned that if reports of the deal's contents were true the Government was "breaking their own agreed position and will be bringing back something that is untenable".
He added that "if the Cabinet agrees it, the party certainly won't".
Asked if the Government's days were numbered he said: "If this is the case almost certainly, yes.
"Because they are in real trouble if they bring back something that is unacceptable to the party.
"The Government puts itself in an impossible position, because they are trying to promote something they themselves said they would never promote. And that makes it impossible.
"How can you ask the party to vote for something which you yourself as Prime Minister and the Cabinet said they would never ever allow?"
Labour leader Jeremy Corbyn said: "We will look at the details of what has been agreed when they are available. But from what we know of the shambolic handling of these negotiations, this is unlikely to be a good deal for the country.
"Labour has been clear from the beginning that we need a deal to support jobs and the economy - and that guarantees standards and protections. If this deal doesn't meet our six tests and work for the whole country, then we will vote against it."
Former EU exit secretary David Davis said last night: "This is the moment of truth. This is the fork in the road.
"Do we pursue a future as an independent nation or accept EU domination, imprisonment in the customs union and second-class status?
"Cabinet and all Conservative MPs should stand up, be counted and say no to this capitulation."
Andrea Leadsom, one of the Eurosceptic ministers who has raised concerns about Mrs May's Brexit plans in recent weeks, had a "good discussion" with the Prime Minister last night and will be at today's Cabinet meeting for further talks with colleagues today, according to a ministerial source.