Theresa May is preparing to rule out a no-deal Brexit after three ministers warned she faces a wave of resignations unless she extends the Article 50 process.
In a major intervention, Claire Perry, Richard Harrington and Margot James called on Mrs May to seek a "short" delay to the UK's departure from the EU rather than risk "ruin" for British businesses under a no-deal outcome.
Writing in the Daily Mail, the three ministers declared: "We can’t go on like this.
"The way to do that is to seek a short extension to Article 50 to allow the negotiations to be completed, the legislation to pass and for the panic that businesses face to subside."
They said that unless May acts, they and other ministers would defy their whips to vote on Wednesday for an amendment in the name of Yvette Cooper and Oliver Letwin which would effectively take no-deal off the table by delaying the Brexit process.
Cabinet ministers Amber Rudd, David Gauke and Greg Clark have also threatened to resign over the issue, and a source familiar with their thinking told PoliticsHome they were "very hopeful" the prime minister will act to rule out a no-deal.
The prime minister is expected to float the prospect of giving the Commons a vote on delaying Brexit when she chairs Cabinet on Tuesday morning.
However, any such move is certain to provoke a furious backlash from Tory eurosceptics, who have insisted the UK must leave the EU on 29 March as planned.
In a sign of the challenge May faces, Perry, James and Harrington all made clear that they were willing to vote in favour of any Commons move to push for the "cool-headed, sensible step" of extending Article 50.
"We implore the government to take that step this week," they said.
"But if the prime minister is not able to make this commitment, we will have no choice other than to join MPs of all parties in the House of Commons, including fellow ministers, in acting in the national interest to prevent a disaster in less than five weeks’ time that we may regret forever."
May was still insisting on Monday that any request to extend Article 50 would not "resolve the issue" of securing a Brexit deal that can win backing in the House of Commons.
Speaking on trip to Sharm El Sheikh in Egypt, she said: "I believe it is within our grasp to leave with a deal on 29 March.
"And I believe that’s where all our energies should be focused.
"Any delay is a delay. It doesn’t address the issue. It doesn’t resolve the issue.
"I think there is, as I say, the opportunity to leave with a deal on 29 March and that’s what we’re going to be working on."