A day after May announced that her team of top ministers had agreed to the terms of the draft deal, Brexit minister Dominic Raab and Work and Pensions minister Esther McVey resigned.
Lawmakers suggested other ministers would quit and eurosceptics in May’s Conservative Party said they had submitted letters calling for a no confidence vote in her leadership.
Two junior ministers and two ministerial aides also quit and the resignations and hostility to the deal from ruling party and opposition lawmakers in parliament left May’s Brexit strategy in doubt and raised the risk of Britain leaving the EU on March 29 without a deal.
Jacob Rees-Mogg, the leader of a Conservative eurosceptic group in parliament, submitted his letter calling for a vote of no confidence in May, saying the draft deal was “worse than anticipated”.
A leadership challenge is triggered if 48 Conservatives write such letters.
May could be toppled if 158 of her 315 lawmakers vote against her.
One eurosceptic lawmaker said more colleagues were either putting in letters or were increasingly minded to do so.
But the prime minister showed little sign of backing down. She told parliament: “The choice is clear. We can choose to leave with no deal, we can risk no Brexit at all, or we can choose to unite and support the best deal that can be negotiated.”
Boris Johnson, a leading critic of May’s Brexit plans who has done little to hide his political ambition, attended a meeting of the European Research Group, where Rees-Mogg and members discussed how many no-confidence letters had gone in.
Rees-Mogg told journalists the next prime minister should be a person who believed in Brexit.
In the markets, sterling fell to a day’s low against the eruo and shares in British companies were hit.
British financial regulators called major banks asking for feedback on market conditions because of sharp falls in the pound and shares, sources said.
In parliament, lawmakers from the ruling and opposition parties spent three hours mostly rubbishing the draft deal, agreed with the EU on Tuesday, which May must get approved by the House of Commons.
Many said it made Britain a “vassal” state, beholden to the bloc’s rules even after leaving.
Others said an agreement on the so-called backstop would tear Britain apart, leaving Northern Ireland all but in the EU’s single market. “It is...mathematically impossible to get this deal through the House of Commons. The stark reality is that it was dead on arrival,” Conservative lawmaker Mark Francois said.
It was the backstop arrangement, which would see Britain and the EU establishing a single customs territory, that spurred most of the criticism. “I cannot reconcile the terms of the proposed deal with the promises we made to the country in our manifesto at the last election,” Raab said.
EU leaders are ready to meet on November 25 to sign off on the divorce deal, or Withdrawal Agreement, but French Prime Minister Edouard Philippe summed up the uncertainty when he said events in London raised concerns about whether it would be ratified.
“We need to prepare ourselves for a no-deal Brexit,” he said.
A group of EU states also raised objections to what has been agreed so far on fishing between the EU and UK after Brexit, diplomatic sources said.
The opposition Labour Party said the government was “falling apart”. “ 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,” said Jon Trickett, a member of Labour leader Jeremy Corbyn’s senior team.
