BORIS Johnson has signalled he may borrow a plan for an early election put forward by the SNP and Liberal Democrats if his own preferred route fails today.

The Prime Minister will ask MPs for a third time to back an election under the Fixed-terms Parliament Act this afternoon, but with little prospect of success.

He needs two-thirds of MPs to support his proposal for an election on December 12 in return for the Commons getting until November 6 to scrutinise and pass his Brexit deal legislation.

However Downing Street said it would look at “all options” for a Plan B, including one similar to a new joint SNP-LibDem plan to use a one-page Bill to secure an election on December 9.

Nicola Sturgeon and LibDem leader Jo Swinson both promoted the idea yesterday, saying it would avoid Mr Johnson’s getting his “bad Brexit deal” passed with the help of rebel Labour MPs.

However, it led to criticism from within the SNP group at Westminster, with one MP publicly announcing he wouldn’t be “bounced” into backing for a move that could help Mr Johnson.

Angus Brendan MacNeil refused to vote to give the PM his “desired present” for Christmas.

Shadow Chancellor John McDonnell said the SNP-LibDem plan had backfired and “come a cropper” with Mr Johnson stealing it for his own ends.

READ MORE: EU preparing to sign off on Brexit extension, according to leaked paper 

EU leaders, who have been asked by the PM to delay Brexit until January 31, are expected to agree to the three-month extension, but with the UK able to leave earlier if Mr Johnson’s can get the Withdrawal Agreement Bill (WAB) passed and so turn his Brexit deal into law.

The Prime Minister’s “do-or-die” promise to leave on October 31 is dead.

Jeremy Corbyn yesterday said even a three-month delay would not be enough to trust Mr Johnson on an election.

He said no-deal was “still there in his mind, it’s still there in the bill, and it’s still there as a threat. It’s got to be completely removed before we’ll support an election. We want an election as soon as that’s removed and it’s in his hands to do so.”

Anticipating defeat for Mr Johnson’s election plan, the SNP-LibDem alternative would see a Bill tabled tomorrow on a one-off amendment to the Fixed-terms Parliament Act (FTPA).

This would see an election held on December 9, giving Mr Johnson too little time to “get Brexit done” before going to the polls, but only if EU leaders agreed to extend Brexit for at least three months.

Crucially, the Bill only requires a simple majority of MPs to pass, meaning it could carry with Tory, SNP and LibDem votes, even if Labour opposed it.

The plan was initially branded a “gimmick” by Conservative Party chairman James Cleverly and a “stunt” by both Culture Secretary Nicky Morgan on the Sunday morning politics shows.

But Number 10 later warmed to it.

A Downing Street source said: “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.”

READ MORE: Labour accuses SNP of ‘political grandstanding’ over election push 

The UK Government has been reluctant to use a Bill to get around the FTPA until now in case it is amended to include votes at 16 or a People’s Vote.

But with the SNP and LibDems no longer making either a pre-condition, getting an early election through a simple majority now looks much more realistic.

A big risk to Ms Sturgeon is that if she facilitates an election that gives Mr Johnson a majority she will be accused of repeating the sin of 1979, when the SNP helped bring down a Labour government and ushered in Margaret Thatcher.

Mr MacNeil, a previous critic of Ms Sturgeon’s approach to Brexit, argued it would be better to keep Mr Johnson “in a cage”, rather than let him win an election and get a hard Brexit.

He warned that the SNP would be likely to lose its place as the third-largest party in Westminster in an election because of a surge for the LibDems.

The Western Isles MP tweeted: “This MP ain’t joining with the LibDems in their latest coalition bid with the Tories!!”

He added: “I am not getting bounced into this... [On] Thursday it was ‘madness’ to have a winter election.

“Any election now will be a Proxy Brexit referendum and Hard Brexit could be won in 6 weeks on only 35% to 40% of the vote!! Tories have been desperate to amend the FTPA! BUT don’t have numbers - even DUP won’t help them Now suddenly this [the SNP/LibDem plan] HALF WAY through a Parl term, to give Boris election he craves.

“SNP won’t even be 3rd party after & Boris in crazy atmosphere could have Maj on 35% for ANY Brexit.”

Councillor Chris McEleny, the former leader of the SNP opposition on Inverclyde, added: “An election will give Tories even greater strength to deliver toxic Brexit. Election should be about independence, not about Brexit, in Scotland.”

Ms Sturgeon defended the plan in a series of tweets on Sunday, warning that doing nothing would allow the PM “to get his bad deal through (with Lab support) or, even worse, run down clock to end January when no deal becomes a real risk all over again”.

She said there was “no evidence” a majority of MPs would back a second EU referendum.

She wrote: “We have no time to waste. For all his bluster, Johnson would much prefer to fight an election with Brexit already ‘delivered’. An election now would instead force him to explain his failure to keep his 31 October ‘do or die’ promise and also defend his bad deal.

“To change the course Johnson is taking us on, we need to beat him. I accept that challenge for the SNP in Scotland. Other parties have to do the same elsewhere in UK. Doing nothing almost guarantees he gets what he wants - Brexit delivered, possibly through ‘no deal’.”

She added: “There are undoubtedly pros and cons but, assuming extension for Jan 31 secured, the case for acting now is strong.”

Ms Swinson told BBC One’s Andrew Marr the Bill removed the threat of no-deal until at least January 31, and so Labour should be able to vote for it.

She said: “This Bill is very straightforward. It would set the date for the next election on December 9.

“The advantage of the Bill is it would enshrine the date into law.”

She said “time pressure” to secure an election meant the “luxury” of votes at 16 was off the cards for now.

The East Dunbartonshire MP also said she would “absolutely not” switch to a safer seat to avoid an SNP challenge.

“I represent East Dunbartonshire, it is the place I grew up, it is my home seat.”

“I won it in 2005, I won it back again in 2017 from the SNP and I will never be complacent but I am confident I will win that seat again if the good people of East Dunbartonshire want me to continue being their MP as well as the leader of the Liberal Democrats.”

Ms Swinson remarked that SNP candidate John Nicholson, who took the seat in 2015, had moved elsewhere to seek re-election to the Commons.

“He has decided this is not a seat he plans to fight me again in,” she said.

Tony Blair said Mr Corbyn was right to resist an election until no-deal was completely ruled out, and that MPs should try to amend the WAB to make sure the UK can only leave the EU with a deal in place.

The former Labour PM told BBC Radio Four’s Westminster Hour: “The sensible thing for him to say to Boris Johnson is, ‘Yes, I’ll agree to your general election, but you’ve got to agree to timetable proper scrutiny of your Bill and allow us to amend that so that we rule out no deal as the outcome of the future negotiation’. Because otherwise Jeremy Corbyn hasn’t prevented no-deal.

“He can make that happen. He can say the moment that’s done properly, he’s up for a general election. But it’s got to encompass the future negotiations and not simply the exit deal.”

He also said that an election and second EU referendum could be held on the same day to break the current impasse, although it was not his preferred option. “You can deal with them both on the same day if you want. But you should deal with them separately,” he said.

It also emerged the PM’s deal waters down the mechanism for enforcing common social, environmental and labour standards after Brexit.

In the UK-EU political declaration, a reference to “adequate” arbitration was replaced by “appropriate”, giving the UK far greater scope to loosen and lower standards.

A leaked memo claimed the change was a win for the UK government that showed its negotiators had “successfully resisted” level playing field commitments.