Theresa May has announced the Cabinet has agreed to back her Brexit deal following a five-hour emergency meeting.

In a statement on the steps of Downing Street on Wednesday evening, the Prime Minister told reporters that frontbenchers had taken “a collective decision” to support her divorce bill following an “impassioned debate”.

“I firmly believe that the draft withdrawal agreement was the best that could be negotiated and it was for the Cabinet to decide whether to move on in the talks,” she said.

“The choices before us were difficult, particularly in relation to the Northern Ireland backstop, but the collective decision of Cabinet was that the government should agree the draft withdrawal agreement and the outline political declaration.”

Her statement came immediately following the lengthy meeting of senior ministers, which began shortly after May urged MPs in the Commons to back her agreement, which she said would bring the UK “significantly closer” to delivering the result of the 2016 referendum.

The PM said the Cabinet’s decision was a “decisive step which enables us to move on and finalise the deal in the days ahead”.

“These decisions were not taken lightly, but I believe it is a decision that is firmly in the national interest,” she added.

“When you strip away the detail the choice before us is clear – this deal which delivers on the vote of the referendum, which brings back control of our money, laws and borders, ends free movement, protects jobs, security and our Union, or leave with no deal or no Brexit at all.”

Tensions were heightened throughout the day on Wednesday by reports that senior Brussels negotiator Sabine Weyand had told ambassadors the deal will mean the UK aligns its rules with Europe, while the EU “will retain all the controls”.

But Weyand – deputy to chief EU negotiator Michel Barnier – cast doubt on the veracity of a leaked note containing her supposed comments by “liking” a series of tweets which said it was “not an accurate reflection of the EU’s position”.

At Prime Minister’s Questions on Wednesday, 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.”

The PM will make a further statement in the Commons on Thursday morning, where she said she fully expects the agreement to come under “intense scrutiny” from MPs.

“It is my job as prime minister to explain the decision government has taken and I stand ready to do that,” she said outside No.10.

Irish Prime Minister Leo Varadkar confirmed an EU summit had now been pencilled in for 25 November to rubber-stamp the deal.

But even after convincing her Cabinet to support the deal, May’s chances of winning a Commons vote currently appear slim, with a sense of unease spreading across the green benches. 

Jeremy Corbyn is expected to order Labour MPs to vote against it.  Speaking during PMQs, he blasted the deal as the “worst of all worlds” that was a “failure in its own terms”.

The Northern Irish DUP, which props up May’s minority government, on Wednesday said it would vote against the deal.

The Tory Brexiteer European Research Group (ERG) of MPs has claimed an “irreducible core” of 40 members are also certain to vote against the PM.

And all 13 Scottish Conservative MPs – including Scotland Secretary David Mundell – signed a joint letter on Wednesday warning May that they could not support a deal which failed to restore “complete control and full sovereignty” over the UK’s fishing waters.

The conservative Bow Group think tank called on the PM to stand down on Wednesday evening, claiming she is unable to deliver on Brexit.

In a statement, it said: “David Cameron left office on the basis that the Brexit result needed a Brexiteer leader and a Brexit government to implement the referendum campaign promises.

“We instead got a Remain-supporting leader and a Cabinet staffed by 70% Remain supporters.

“Theresa May has demonstrated with her final deal that she has been unable to implement what the British people voted for in Brexit, it is therefore time for her to stand aside.”