Downing Street has suggested Boris Johnson could back opposition plans to trigger an election on December 9, a move that would deny the prime minister the opportunity to get his Brexit bill through parliament ahead of a snap poll.
Mr Johnson will dare MPs to vote on Monday for a pre-Christmas election on December 12, allowing him to bring his deal back to the Commons for scrutiny and give parliament until November 6 to approve the enabling legislation.
Under the 2011 Fixed-Term Parliaments Act, Mr Johnson needs to obtain cross-party support and the backing of at least 434 MPs. Northern Ireland’s Democratic Unionists have said that they will use their 10 Westminster votes to defeat the government.
The Labour leader Jeremy Corbyn is expected to order his MPs to abstain and other opposition parties have also indicated they will vote against Monday’s motion.
A one-page bill drawn up by the Liberal Democrats for a December 9 election would only require the support of a simple majority of MPs in a vote on Tuesday.
The Lib Dems and the Scottish National Party have argued the bill would prevent Mr Johnson rushing his deal through the Commons ahead of an election, as well as remove the threat of a no-deal Brexit.
It also states that the election would be cancelled if the EU decided not to grant a three-month Brexit extension later this week.
A Downing Street official said: “Tomorrow MPs will vote on an election on 12 December so we can get a new Parliament. If Labour oppose being held to account by the people yet again, then we will look at all options to get Brexit done including ideas similar to that proposed by other opposition parties.”
The official added: “We can’t allow parliament to waste 2020 the way it has wasted 2019 — the country wants Brexit done so we can move on and focus on the public’s priorities.”
Diane Abbott, the shadow home secretary, said her party would discuss the Lib Dem/ SNP proposal with opposition colleagues and called for Mr Johnson to unequivocally rule out a no-deal Brexit, ahead of Monday’s vote.
She told the BBC’s Andrew Marr show: “One way of doing it is for Boris Johnson to come to the floor of the house and give the House of Commons a commitment that whatever happens, he will not take Britain out of the EU without a deal.
“If he said clearly and unequivocally that ‘I will not take Britain out of the EU without a deal,’ I think not just the Labour Party would be satisfied . . . a lot of Conservative MPs would be satisfied. Let’s wait to see if he does that.”
Ms Swinson said her bill would remove the threat of no-deal through a Brexit extension, until at least January 31.
Under the one-line act of parliament, opposition parties could seek to alter its substance. But speaking to the BBC, Ms Swinson said the Lib Dems would not seek to add amendments to the bill, such as votes for 16-year-olds.
“I recognise the time pressure that we are under right now doesn’t give us that luxury — January 31 isn’t that far away”, she said.
“I think we have to pass this as it is drafted. We cannot assume we will keep getting an extension to Article 50. We do need to resolve this issue.”
The initial auguries were far from positive for the Lib Dems and SNP on Sunday morning, with Nicky Morgan, the culture secretary, branding the bill a stunt. James Cleverly, the Tory party chairman, also denounced the plan as a gimmick.
Mr Cleverly said: “We put forward proposals for a general election first. But also the delivery of Brexit.
“It’s clearly a gimmick. It moves the election date by three days and takes the Withdrawal Agreement Bill completely off the table.
“If they really want to vote for an election they can vote for the bill we put forward.”