Theresa May has urged Cabinet ministers to act in the national interest and support a Brexit deal which takes the UK “significantly closer” to delivering the result of the referendum.

The Prime Minister is facing a crunch showdown with Brexit-backing ministers as she seeks to persuade her senior team to back a draft deal on the UK’s withdrawal from the European Union.

Tensions over the proposed agreement were heightened by reports that a senior Brussels negotiator has said the deal will mean the UK aligns its rules with Europe, while the EU “will retain all the controls”.

At Prime Minister’s Questions, Mrs May told MPs: “The Cabinet will decide on the next steps in the national interest.

“I am confident that this takes us significantly closer to delivering what the British people voted for in the referendum.

“We will take back control of our borders, our laws and our money, leave the Common Fisheries Policy and the Common Agricultural Policy while protecting jobs, security and the integrity of our United Kingdom.”

Labour leader Jeremy Corbyn said the draft deal was “a failure in its own terms” and a senior spokesman said that the “likelihood” was that the party would vote against it in the Commons.

Irish premier Leo Varadkar said the draft deal could provide the basis for a summit of EU leaders by the end of the month, potentially on November 25.

POLITICS Brexit
(PA Graphics)

“It is yet to be agreed by the UK Government and they will discuss it this afternoon, and it is yet to be agreed by the European Council, and we may be in a position to have an emergency European Council meeting before the end of the month to do exactly that,” he said.

Amid feverish speculation about possible Cabinet resignations, Leave-backing Conservatives including Boris Johnson and Jacob Rees-Mogg called on ministers to reject the proposed agreement, which they fear could lock Britain in the EU’s customs union indefinitely, blocking its ability to strike new trade deals elsewhere.

DUP leader Arlene Foster headed for London with a warning that she would not back a deal which leaves Northern Ireland “adrift in the future”.

A leaked diplomatic note obtained by The Times suggested that Sabine Weyand – deputy to EU chief negotiator Michel Barnier – told ambassadors the UK “would have to swallow a link between access to products and fisheries in future agreements” and it also indicated that close customs alignment should remain indefinitely.

According to the note, Ms Weyand said: “We should be in the best negotiation position for the future relationship. This requires the customs union as the basis of the future relationship.

“They must align their rules but the EU will retain all the controls. They apply the same rules. UK wants a lot more from future relationship, so EU retains its leverage.”

However, questions were raised over the leaked note after Ms Weyand “liked” a series of tweets suggesting that it was “not an accurate reflection of the EU’s position”.

The draft agreement of more than 400 pages is understood to involve the UK remaining in a customs union and committing to a “level playing field” on EU rules in areas like environmental and workplace protections during a backstop period after Brexit.

Cabinet ministers are also looking at a brief political declaration – possibly as short as five pages – setting out an outline framework agreed by EU and UK negotiators for future relations on issues like trade and security. This outline remains open for further negotiation ahead of any summit and a final deal will depend on it being acceptable to the UK in its full form.

POLITICS Brexit
(PA Graphics)

In an apparent response to Ms Weyand’s comments, the Prime Minister said: “I am aware of the concerns that there are, that we don’t want to be in a position where the European Union would find it comfortable to keep the UK in the backstop permanently.

“That’s why any backstop has to be temporary.”

The “backstop” is intended as a fallback arrangement to avoid a hard border with Ireland unless a wider trade agreement can resolve the issue.

Brussels is understood to have dropped its demand for Northern Ireland alone to remain within the EU customs area until a new trade deal is implemented, but the province could be subject to a different regulatory regime.

The Guardian reported that an independent arbitration committee will judge when the backstop could be terminated, with a review six months before the end of the separate transition period in December 2020.

At Westminster, speculation over possible resignations focused on Brexit-backing ministers such as Penny Mordaunt, Andrea Leadsom and Esther McVey.

POLITICS Brexit
(PA Graphics)

Sources close to Brexiteer ministers played down the prospect of walkouts, saying “don’t expect fireworks today”.

Mrs Leadsom told ITV’s Good Morning Britain she had had “a good conversation” with the Prime Minister and was “extremely optimistic that we’ll have a good deal”, while Ms Mordaunt is understood to be still waiting for more information about the proposals.

Brexit protest
Protests outside Downing Street ahead of the Cabinet meeting (Andrew Matthews/PA)

Former Tory leader Lord Hague warned Brexiteers that if they did not accept Mrs May’s deal, Britain might not leave the EU.

He told BBC Radio 4’s Today programme: “If you are those sceptics, the ardent Brexiteers, what you have to really worry about here is that if you don’t take this opportunity to leave the EU, to get Brexit over the line, you might never leave at all.”

Former Brexit secretary David Davis urged his former Cabinet colleagues to “say no to this capitulation”, while Mr Johnson said they should “chuck it out”, warning that the proposals made a “nonsense of Brexit”.

Brexit-backing Tory MP Andrew Bridgen said: “This isn’t Brexit, it’s not even close to Brexit.

“If it were darts, it’s not missing the board, this is not even the right wall.”