Work and Pensions Secretary Esther McVey has resigned the Cabinet saying the Brexit deal "does not honour the result of the referendum".

Her move comes just two hours after Brexit Secretary Dominic Raab sensationally quit his post in a massive blow to Theresa May's Brexit plans.

Anne-Marie Trevelyan, an an Education Parliamentary Private Secretary, and Brexit Minister Suella Braverman have since followed.

LIVE: Raab quits as May prepares to update Commons

Mr Raab, who only took over in the summer after David Davis resigned in protest over the Prime Minister's withdrawal strategy, said he "cannot in good conscience support the terms proposed for our deal with the EU".

His surprise departure came amid a furious backlash from Brexit-backing Tories to the deal agreed by UK and EU negotiators four months ahead of the UK's scheduled withdrawal on March 29.

Hours earlier Shailesh Vara had quit as minister of state for Northern Ireland, saying Mrs May's agreement, "leaves the UK in a halfway house with no time limit on when we will finally be a sovereign nation".

Echo:

In his letter to the Prime Minister, Mr Raab said the deal represented a "very real threat to the integrity of the United Kingdom" because of provisions for Northern Ireland.

He also said he could not accept "an indefinite backstop arrangement" for the Irish border.

He said: "No democratic nation has ever signed up to be bound by such an extensive regime, imposed externally without any democratic control over the laws to be applied, nor the ability to decide to exit the arrangement."

Mr Raab added: "Above all, I cannot reconcile the terms of the proposed deal with the promises we made to the country in our manifesto at the last election.

"This is, at its heart, a matter of public trust."

The resignations came as European Council president Donald Tusk announced an extraordinary meeting of EU leaders in Brussels on November 25, at which the withdrawal agreement and a political declaration on future relations will be finalised and formalised.

Westminster is braced for further resignations, amid widespread expectations that the Prime Minister may face a challenge to her position from Conservative MPs submitting letters of no confidence in her leadership.

Mr Raab had been a surprise choice as Brexit Secretary when Mr Davis, along with foreign secretary Boris Johnson and Brexit minister Steve Baker, resigned in protest at Mrs May's Chequers plan in July.

LIVE: Raab quits as May prepares to update Commons

As the UK's ministerial point man in negotiations he made repeated trips to Brussels for talks with EU negotiator Michel Barnier as he and civil servants tried to hammer out a workable withdrawal agreement.

The pound fell heavily against most major currencies after his resignation. Sterling dropped 1.1% to 1.28 US dollars and was 1.2% lower at 1.13 euros.

Shadow Cabinet Office minister Jon Trickett said the Government was "falling apart before our eyes as, for a second time, the Brexit Secretary has refused to back the Prime Minister's Brexit plan".

"This is the 20th minister to resign from Theresa May's Government in her two-year premiership," he said.

"Theresa May has no authority left and is clearly incapable of delivering a Brexit deal that commands even the support of her Cabinet, let alone Parliament and the people of our country."

Remain-supporting Tory MP Anna Soubry added on Twitter that Mr Raab's resignation "marks the end of PMs Withdrawal Agreement" and possibly her premiership.

Ms Soubry added: "No PM deserves to be so badly treated.

"Raab signed up to her Withdrawal Agreement allowing her to make her statement after Cabinet knowing he'd resign in time for the 9am News bulletins the next morning. Shameful."

Mrs May now faces a battle to get it through Parliament as pro-Leave Conservative MPs - as well as some Remainers - lined up to condemn the plan, accusing her of breaking promises and leaving the UK at the mercy of Brussels.

In a resignation statement, North-West Cambridgeshire MP Mr Vara - who was promoted by Mrs May as recently as July - said: "We are a proud nation and it is a say day when we are reduced to obeying rules made by other countries who have shown that they do not have our best interests at heart.

READ MORE: Has Theresa May got the numbers for her Brexit plan?

"We can and must do better than this. The people of the UK deserve better."

Mr Vara, a former Conservative vice chairman who has served as a whip and on the frontbenches for the bulk of his career since entering Parliament in 2005, backed Remain in the 2016 referendum.

In Brussels, Mr Tusk was handed a copy of the 585-page withdrawal agreement by EU chief negotiator Michel Barnier.

Ministers and ambassadors of the remaining 27 EU states will work to finalise by next Tuesday the political declaration on future relations with the UK, published in outline form on Wednesday, he said.

Welcoming the UK Cabinet's collective agreement to accept the withdrawal document, Mr Tusk said: "Of course, I do not share the Prime Minister's enthusiasm about Brexit as such.

"Since the very beginning, we have had no doubt that Brexit is a lose-lose situation and our negotiations are only about damage control."

And he sent a message to the British people: "As much as I am sad to see you leave, I will do everything to make this farewell the least painful possible, both for you and for us."