Theresa May has moved to prevent possible ministerial resignations by allowing Conservative MPs a free vote when the House of Commons passes its judgment on different Brexit options on Wednesday evening.
But the Prime Minister herself, along with her Cabinet ministers, will abstain in the “indicative votes”, whips have indicated.
Mrs May was warned she could face “north of a dozen” resignations if she tried to force ministers to toe her line when the Commons votes on eight options, ranging from no-deal to a second referendum, a customs union or revocation of the Article 50 letter triggering Brexit.
Meanwhile, Labour MPs have been told to back a motion tabled by former foreign secretary Dame Margaret Beckett, which would require any Brexit deal passed during this Parliament to be confirmed in a public referendum before ratification.
Jeremy Corbyn’s party is also whipping its MPs to back its own alternative Brexit plan as well as a customs union proposals tabled by veteran Tory europhile Ken Clarke.
And they are being encouraged to back Nick Boles’s “Common Market 2.0” proposal for single market membership and a close customs arrangement, which Mr Corbyn himself will support.
Speaker John Bercow selected just eight out of the 16 Brexit options tabled by MPs for a vote, turning down proposals to demand a unilateral right to leave the Northern Irish “backstop” or to require automatic revocation of Article 50 if no deal is reached.
He did not select the Malthouse Compromise Plan A drawn up by backbenchers from Leave and Remain wings of the Tory Party, which would have implemented Mrs May’s deal with the backstop replaced by alternative arrangements.
Mrs May has said she will not regard the results of Wednesday’s votes – and a follow-up session next Monday designed to find a consensus solution – as binding.
But Mr Clarke told BBC Radio 5 Live’s Emma Barnett that the Prime Minister “would obviously have to be removed” if she ignored a consensus emerging from the indicative votes process.
Mrs May is likely to face calls from Tory MPs for her to name a date for her departure as a price for their support for her deal, when she addresses the backbench 1922 Committee before Wednesday’s votes.
Brexit Secretary Steve Barclay said he was tabling a motion to enable the House to hold a vote on Friday – which would otherwise be a non-sitting day – if ministers believe they have the support to get it through.
However, Mr Bercow warned he would not allow ministers to use procedural devices to circumvent his ruling, prompting a Government source to accuse him of “making it up as he goes along”.
Securing a “meaningful vote” this week would mean the Government had met the deadline set by the EU for an extension of the Article 50 withdrawal process to May 22 to allow it to complete the preparations for leaving.
Her comments came as a number of leading Conservative Brexiteers signalled they were ready to fall into line amid fears Brexit could be lost altogether if it does not get through.
Jacob Rees-Mogg, the chairman of the European Research Group, told Today: “I think that we have got to the point where legally leaving is better than not leaving at all.
“Half a loaf is better than no bread.”
“I won’t abandon the DUP because I think they are the guardians of the union of the United Kingdom,” he said.
His comments came after Brexit figurehead Boris Johnson hinted on Tuesday he might be ready to swing behind the deal.
“If we vote it down again, for the third time, there is now, I think, an appreciable risk that we will not leave at all,” he told an audience of Daily Telegraph readers.
But the former foreign secretary stressed he was “not there yet” and indicated a change at the top of the party may be required to win him over.
“If people like me are to support this deal… then we need to see the proof that the second phase of negotiations will be different from the first,” he said.
In a highly unusual change to normal procedures, MPs will take part in a paper ballot voting Yes or No to each of the options selected by the Speaker.
The Leader of the House Andrea Leadsom again warned the Government would not necessarily be bound by the outcome as some of the options were “undeliverable”.
“We will look very carefully at it but the reality is that it may not be negotiable and certainly not within the time frame,” she said.
The architect of the cross-party plan, Tory former minister Sir Oliver Letwin, warned MPs could force the Government to act if it tried to ignore the results.
“Those who I am working with across the parties will move to legislate to mandate the Government – if we can obtain majorities in the House of Commons and House of Lords for that – to carry that forward,” he told the Today programme.