Dominic Raab has sensationally quit as Brexit Secretary, in a massive blow to Theresa May's Brexit plans.
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 on Thursday 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".
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."
He 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.
Commenting ahead of the Prime Minister’s Commons Statement on the Withdrawal Agreement,Federation of Small Businesses (FSB) National Chairman Mike Cherry, said: “With 20 weeks left until exit day, many small businesses will be relieved to finally see some progress being made. An agreed draft Withdrawal Agreement is a significant step back from the cliff edge which would result in a chaotic no deal Brexit that would be deeply damaging and dangerous for our small firms.
“If this deal passes parliament, small businesses will be given the security of a transition period which will allow them to carry on operating as they do now from the 29th of March 2019 until at least the end of 2020. This brings with it some certainty that our small businesses have craved. It will hopefully lead to businesses pushing the go button on investment decisions that have been on pause as they waited for a better understanding of the medium term trading landscape post Brexit day.
“Negotiations must now move quickly onto nailing down our future trading relationship with the EU post July 2020. Whatever option is agreed upon, it is essential that our small firms are given sufficient time and support to prepare for any changes.
“A deal is now on the table and it is important that the UK Government and EU press ahead as this is the best chance of avoiding a catastrophic cliff edge that would disproportionately harm smaller businesses who are the engine of the UK economy.”
Commenting on the announcement from the Prime Minister that the Cabinet has backed the draft Withdrawal Agreement and the political declaration on the future relationship between the UK and the EU27, Babs Murphy, chief executive of the North & Western Lancashire Chamber of Commerce said: “Businesses now need absolute clarity on the actual trading terms they are likely to face in future and at this stage we recognise that many are yet to be agreed. The avoidance of sudden or multiple changes to trading conditions is crucial to our exporters as well as business investment and confidence.
“The Prime Minister has made huge efforts to get to this point and I am sure the business community recognises that. Businesses will now be looking carefully and deliberately at the real-world implications of this agreement over the coming days, and expect their elected representatives to do the same. With people’s livelihoods and the future prospects for many companies in the balance, this is not the time for snap judgments.
“Our priority now is to assess the implications of these proposals, working closely with our local business community”