Theresa May was dealt a blow on the morning after Cabinet agreed her Brexit plan, as a minister resigned from her Government saying that the British people "deserve better" than the deal on offer.
Shailesh Vara quit as minister of state for Northern Ireland, saying he cannot support Mrs May's agreement, which he said "leaves the UK in a halfway house with no time limit on when we will finally be a sovereign nation".
His resignation 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.
Mr Vara's departure comes 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.
Westminster was 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.
The Prime Minister cleared the first hurdle when Cabinet ministers finally approved the draft terms of her agreement with Brussels at a stormy five-hour meeting on Wednesday.
With much sadness and regret I have submitted my letter of resignation as a Northern Ireland Minister to the Prime Minister. A copy of my letter is attached.
It has been a joy and privilege to serve in the Northern Ireland Office and I will always cherish the fondest memories. pic.twitter.com/SN8j4OwhYD— Shailesh Vara MP (@ShaileshVara) November 15, 2018
But she 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.
"We can and must do better than this. The people of the UK deserve better."
- Press Association