Boris Johnson has threatened to pull his Brexit deal and call for an early general election if MPs do not vote for his plans as he kicked off a Commons showdown.

Two crucial votes on Tuesday evening will determine whether the Prime Minister will be able to live up to his “do or die” commitment to take the UK out of the European Union by the October 31 deadline.

MPs will cast their initial vote on the PM’s Withdrawal Agreement Bill (WAB) before being asked to back his accelerated timetable to hurry the legislation through Parliament.

But the PM told the Commons that he would “in no way allow months more of this” as he called on MPs to work “night and day” to scrutinise his plans and avoid a no-deal departure.

“If Parliament refuses to allow Brexit to happen, and instead gets its way and decides to delay everything until January or possibly longer, in no circumstances can the Government continue with this,” he said.

“And with great regret I must say that the Bill will have to be pulled and we will have to go forward to a general election.”

The threat was dismissed as “childish blackmail” by Liberal Democrat Brexit spokesman Tom Brake.

“MPs shouldn’t be bullied into voting in favour of this ridiculously short timetable,” he added.

Mr Johnson also warned that failure to back his plans would be “closing the path to leaving with a deal on October 31 and opening the path to a no-deal in nine days time”.

Urging MPs to vote for the programme motion, he said: “Doing anything else would, I am afraid, mean this House abdicating its responsibilities and handing over to the EU Council what happens next.”

A programme motion is thought to have only been defeated once before – on House of Lords reform in 2012 – and the Bill was then scrapped.

Countdown to leaving the EU
(PA Graphics)

Labour leader Jeremy Corbyn said he would vote against both aspects and accused the PM of “trying to blindside” Parliament with a “disgraceful attempt to dodge accountability, scrutiny, and any kind of proper debate”.

But there was a sign the PM’s threat may be effective when Sir Oliver Letwin, an exiled Tory who has been key in efforts to thwart a no-deal, said he was “seriously worried” the Bill would be pulled if the timetable was voted down.

“Surely best for all of us who regard this deal as the least of the evils to vote for the programme motion, whatever we really think of it,” he added.

Labour’s chief whip Nicholas Brown offered an olive branch to Mr Johnson by telling him he was “available at any point to seek a consensus with you on a programme motion that would command the support of all sides of the House”.

In a letter to the Prime Minister, he added: “No parliamentarian seeking to properly scrutinise and improve such a vital piece of legislation could agree to support the Government’s proposed programme motion.”

Donald Tusk gave some reassurance to MPs that a requested extension to Article 50 would be treated with “all seriousness” as he consults with EU leaders who could block the move.

“It is obvious that the result of these consultations will very much depend on what the British Parliament decides, or doesn’t decide,” the European Council president said.

“We should be ready for every scenario. But one thing must be clear: as I said to Prime Minister Johnson on Saturday, a no-deal Brexit will never be our decision.”

The new Brexit deal must also win backing from the European Parliament, but its Brexit co-ordinator, Guy Verhofstadt, said problems affecting EU nationals in the UK must first be solved to prevent “another Windrush scandal”.

As his time as European Commission president comes to a close, Jean-Claude Juncker said it has “pained” him to spend so much time dealing with Brexit, which he described as “a waste of time and a waste of energy”.

EU chief negotiator Michel Barnier also told the European Parliament that “this is the only possible agreement”, signalling it is the last deal any PM can broker.

Rory Stewart, who was among the 21 rebels against no-deal exiled from the Tories, suggested he could back the WAB but not back the programme motion.

Failure to get the motion through would open up the prospect that Mr Johnson will be forced to accept another lengthy delay to Britain’s departure – something he has vowed not to do.

The first vote on Tuesday will be on the Bill’s “in principle” second reading.

Despite the opposition of the DUP over arrangements for Northern Ireland, ministers believe they have the support of pro-Leave Labour rebels and former Tory MPs now sitting as independents, who would rather leave with Mr Johnson’s deal than no deal at all.

If it passes under the proposed timetable the Bill would then move to the committee stage – which will continue on into Wednesday – when MPs will have the opportunity to put down amendments.

Labour-backed amendments are expected to include attempts to keep the UK more closely aligned with the EU through a customs union and to hold a second referendum.

Both are bitterly opposed by the Government.