BORIS Johnson stuck the boot into embattled Theresa May last night as he positioned himself as the man to rescue Brexit in time for Christmas.

The former Foreign Secretary blasted the “failure”, weakness and “pessimism” at the heart of her government on the eve of a crunch vote that could trigger her downfall.

In a brazen pitch for her job, he unveils his own manifesto for taking on EU bullies and winning a deal that works for everyone.

BoJo was first out of the traps as wannabe leaders secretly began drawing up their plans for power if Mrs May is brought down by a humiliating Commons defeat on Tuesday.

He promised that he would not hand a penny of the £39billion divorce bill to the EU until the hated backdrop - which could keep Britain trapped in the customs union - is ditched.

If they agree, he will give them half the cash and tell them the rest will follow once we have agreed a “generous zero tariff, zero quota free trade deal”.

Writing in The Sun on Sunday, Mr Johnson says: “It is time now to show our EU friends that we mean business.

“This should be a take it or leave it offer - and to show that we mean business we must be able to walk away.”

He vowed he is ready to manage our departure with “energy and conviction” and contrasted it with “that lack of resolve that has so weakened our hand in the talks.”

Boris said he is not cowed by fear of leaving without a deal and added: “It is time to get on with it and remember, if we have to go down this route, we will have the entire £39billion to spend on it.”

Mrs May will decide on Monday whether to persist with her doomed withdrawal plan when government whips tell her exactly the full scale of the expected thrashing.

Ministers have pleaded with her - so far without success - to postpone the vote and plead for extra sweeteners from the EU at a summit on Thursday.

Tory Brexiteer Will Quince quit as ministerial aide to Defence Secretary Gavin Williamson after joining the growing list of rebels.

His departure brings the number of government members who have resigned over Brexit to eight.

But up to six more are said to be ready to quit rather than back her loathed Brexit plan which has enraged Leavers and Remainers alike.

International Aid Secretary Penny Mordaunt - a pro-Brexit minister - has still not uttered a word in favour of the deal and was said to be waiting in the hope of a better deal emerging.

She has also been tipped as a future leadership contender but is yet to make a move.

Mrs May faces a threat on three fronts if, as expected, her loathed Brexit plan is thrown out by a huge majority.

Labour is planning a no-confidence vote in the Commons and enough Tory MPs could hand in are ready to hand in letters calling for a leadership race.

Exasperated Tory grandees dubbed “the men in grey suits” plan to demand a showdown with her and Number 10 advisers within minutes if the margin of defeat runs into three figures.

One said: “Part of the reason we are in this mess is that she won’t listen to anybody apart from the small clique around her.

“If Tuesday’s vote ends in a defeat of seismic proportions, then we are going to have to tell her straight that it’s time to go.”

Two former Brexit Secretaries David Davis and Dominic Raab - who both quit over the deal - were seen sharing a glass of wine last week as talk of leadership plots hit fever pitch.

Mr Davis warned the Tory leadership against trying to “bully” MPs into backing Theresa May’s deal.

He said: “The decisions taken in the next few months will dictate our nation’s future for a generation.

“We will be judged in the future as to whether we flinched in the face of unfounded threats and panic, or stood up for our national interest and took our proper place in the world.

“To do this, we need to preserve our freedom of action on trade, on regulations, on migration, on fishing.

“We must not subordinate ourselves to partisan foreign institutions. Democracy demands no less.

"The Conservative Party has a key role in this.

"That role is not to attempt to bully MPs into support for a failed strategy. Our role is to come together to find a joint approach that supports the decision of the referendum and promotes the national interest.”

Work and Pensions Secretary Amber Rudd said the country would be in “uncharted territory” if MPs reject Theresa May’s Brexit deal.

“If we don’t get it through, anything could happen, most unwelcome,” she told BBC Radio 4’s Today.

She rejected suggestions that the Prime Minister would have to quit if she lost the vote: “I hope that we would regroup and get on with being able to address the difficulties that would then occur but hold stable, hold firm, while we get on with government.”

She added: “What would be a complete mistake would be to allow what is already an unstable period to descend into further instability with talk of a leadership change.”

Fresh cracks appeared in the Cabinet yesterday with ministers hopelessly divided on the way forward - and several harbouring leadership ambitions.

She insists she would vote Remain again if there were a second referendum adding: “I think we’re better off in.”

The Cabinet is also split over whether to hold a second referendum to break the stalemate.