The two sides were said to be “at loggerheads” late on Tuesday, setting the scene for a nailbiting vote designed to guarantee the UK cannot crash out of the EU without an agreement.
The Independent was told that Theresa May had called in some of the rebels to persuade them personally to back down – with the government increasingly confident that its arm-twisting was succeeding.
But one backbencher behind the revolt dismissed the claim that it was poised to fail because some of its supporters were being “turned”.
“That is a classic whips’ operation,” he said. “There’s no evidence that the people who said they would vote with us are peeling away.”
Anna Soubry, another leading rebel, insisted they would not be cowed, despite huge public pressure, tweeting: “Death threats becoming routine & making many of us more resolute.”
And she quoted Winston Churchill to rebut allegations that she is a “traitor”, saying: “The first duty of a member of parliament is to do what he thinks in his faithful and disinterested judgement is right and necessary for the honour and safety of Great Britain.”
Defeat would be hugely damaging for Ms May, triggering fury among her pro-Brexit MPs – who insist no deal must remain an option – and allegations of weakness.
The vote will be on “Grieve 2”, a reworked amendment to the EU withdrawal bill put forward by Dominic Grieve, the former attorney general.
It would force ministers to give MPs a vote on the next steps if they accept, by 21 January 2019, that there is no prospect of an agreement with the EU.
A rebellion was aborted last week only when the prime minister partially agreed to the rebels’ demands for MPs to have that decisive vote to prevent a no-deal exit.
They were stunned when the amendment was later altered, so that MPs would only be able to debate a no-deal outcome – rather than change the government’s course.
The new Commons clash was set up when the House of Lords backed the Grieve proposals on Monday evening by a whopping majority of 119 votes.
One former cabinet minister said the result was “touch and go”, with around 14 Tories required to join the revolt to defeat the prime minister.
There were signs of a growing number of Labour MPs ready to vote with the government – after five did last week, plus one currently suspended from the party.
One who abstained last week told The Independent that opposition to the amendment was growing on the Labour benches, despite whips’ pressure.
“For me this is now also about the House of Lords – they are meant to be an advisory chamber, but they are attempting to tell us what to do,” he said.
On the likely result, he added: “No one can give an accurate figure because not everyone has been spoken to yet.”
No 10 refused to compromise further, a spokesman saying: “We cannot accept the amendment on a meaningful vote agreed in the Lords.
“Agreeing to amendable motions would allow parliament to direct government on its approach to exiting the EU, binding the prime minister’s hands and making it harder to secure a good deal for the UK.”
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