Theresa May secured Cabinet approval to proceed with her deal on UK withdrawal from the EU after an “impassioned” five-hour meeting featuring dissent from a number of ministers.

Reports suggested as many as a third of the 28 ministers attending voiced doubts about the draft agreement drawn up by UK and EU negotiators after 19 months of talks in Brussels.

No vote was taken but Cabinet backed the 585-page document – along with a shorter outline political declaration on future EU-UK trade relations – by consensus.

However the PM faced a backlash from Tory Brexiteers, with Jacob Rees-Mogg saying he could not support it, and hoped other Tory MPs would follow suit.

Mrs May described the debate around the Cabinet table as “long, detailed and impassioned”, in a clear indication her proposals had come under intense challenge from ministers.

There were no threats to resign during the meeting, which ended with ministers toasting the agreement with red and white wine.

Rumours of possible walkouts continued to swirl around Westminster, however, and the level of Brexiteer discontent has raised expectations of further letters of no confidence in Mrs May from Tory MPs.

Sources said the delivery of letters to the chairman of the backbench 1922 Committee Sir Graham Brady was “imminent”, with a total of 48 needed to trigger a vote on Mrs May’s position.

European Commission president Jean-Claude Juncker issued a statement that “decisive progress” had been made, clearing the way for a special summit for leaders of the remaining 27 EU states to give their stamp of approval, probably on November 25.

Speaking outside 10 Downing Street minutes after the crunch Cabinet meeting concluded, Mrs May acknowledged she faced “difficult days ahead” as she prepares to seek the backing of the House of Commons in what is expected to be the toughest vote of her parliamentary career.

Brexit
Theresa May spoke outside Downing Street following a five-hour Cabinet meeting (Victoria Jones/PA)

She said: “I firmly believe, with my head and my heart, that this is a decision which is in the best interests of the United Kingdom.”

Senior UK Government officials said the final text of the withdrawal agreement featured important gains for the UK on the so-called backstop arrangements to be implemented if no trade deal can be reached.

The outline political declaration – which will be subject to further negotiation over the coming weeks – expresses an ambition to achieve zero tariffs and no quotas in EU-UK trade, something the officials said no other major economy had achieved.

The facilitated customs arrangements and “common rulebook” proposed in Mrs May’s Chequers plan are replaced by the concept of a “sliding scale” of commitments and market access, which means the UK would not be tied to an off-the-shelf deal of the kind previously offered to countries such as Canada.

“We are for the very first time opening up a world where we can do the sort of trade deal the EU has never done before,” one UK official said.

Under backstop arrangements designed to keep the Irish border open, if no trade deal is agreed by the end of the transition period in December 2020, a temporary “EU-UK single customs territory” would be established.

This could be terminated only by mutual consent of Brussels and London but each side would be legally bound to make “best endeavours” to bring it to an end by sealing a permanent deal on their future relations.

There will be a provision to allow the two sides to extend the transition to a fixed date rather than activate the backstop.

A five-person arbitration panel, with two representatives of each side and one independent member, will be set up to rule on disputes, with the chair chosen by drawing lots if members cannot agree.

In Brussels, chief negotiator Michel Barnier said a free trade agreement should not take as long as it has with other countries and he believed it was “feasible” to complete it within the transition period.

Mrs May described the deal as “the best that could be negotiated”.

“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,” she said.

Her deal was condemned by leading Brexiteers.

Prominent Leaver Peter Bone warned Mrs May in the Commons that she risked losing the support of “many Conservative MPs and millions of voters across the country”.

Letter from Jacob Rees-Mogg to all Conservative MPs (PA)

The chairman of the European Research Group of Eurosceptic Tories, Jacob Rees-Mogg, wrote to Conservative MPs calling on them not to support Mrs May’s plan, arguing the UK would “hand over £39 billion to the EU for little or nothing in return”.

The deal is “unacceptable to unionists”, will “lock us into an EU customs union and EU laws” and is “profoundly undemocratic”, Mr Rees-Mogg said.

Meanwhile, Arlene Foster, whose DUP party props up Mrs May’s minority administration in the Commons, warned the PM there would be “consequences” if her deal treats Northern Ireland differently from the rest of the UK.

Mrs Foster met Mrs May for private talks following the marathon Cabinet meeting and the Prime Minister also called the leaders of the Scottish and Welsh devolved administrations.

Scottish First Minister Nicola Sturgeon said the deal was “bad for Scotland”, comparing it to being “blackmailed into a choice between the frying pan or the fire”.

Liberal Democrat leader Sir Vince Cable said: “The crucial change is that the Prime Minister and the Government have admitted for the first time that the choice for the country is not just between this bad deal or ‘no deal’.  Instead, ‘No Brexit’ is a very real possibility.

“It is time to return this issue to the country and give people the option to Remain.”