Former attorney general Dominic Grieve said he would force a vote on an amendment to the EU (Withdrawal) Bill unless ministers back down.
Up to 20 Conservative MPs are thought to be willing to support the change in a vote tonight. Further amendments on keeping the UK in a variety of EU agencies and agreements are being put forward by the SNP. “I think there are quite a few who may support me – I think enough, if this comes to a vote, to defeat the government,” Mr Grieve told the BBC. “I think there is a real possibility that it will happen.”
Brexiteers reacted angrily to the threatened revolt, accusing the rebels of trying to “derail” the whole bill, which is needed to transpose EU legislation on to the UK statute book when Britain leaves in March 2019.
Mr Grieve, who campaigned for Remain in the referendum, denied his amendment – which would require any final deal with the EU to be approved by a separate act of Parliament – was designed to prevent Brexit happening.
“I don’t want to defeat the government,” he said. “I would much prefer the government to listen.”
It comes as a YouGov poll found that 53 per cent of people would like the UK’s final Brexit deal to be approved by MPs or put to the public.
The poll, commissioned by the Best for Britain campaign, found 32 per cent of people think there should be a referendum on the UK’s final Brexit deal, while a further 21 per cent believe MPs should get the final say. That compares to 33 per cent of people who say the UK should leave on whatever terms the government secures.