At least a dozen Tory MPs are ready to quit the party to stop Boris Johnson becoming leader.

They issued the warning last night after he sparked outrage by saying Theresa May’s Brexit strategy had put Britain in a suicide vest and handed the detonator to Brussels.

Mr Johnson’s critics accused him of using disgusting language to distract attention from his private life.

And today the PM's official spokesman slapped down Mr Johnson over the comments.

He said: ‘This is not the language that the Prime Minister would choose to use. Beyond that, I don’t plan on giving this article further oxygen.

‘The PM is fully focused on Brexit negotiations which are at a very important and intense stage, and on delivering on the verdict of the British people.’

Mr Johnson is being divorced by long-suffering wife Marina over claims of another affair.

Boris Johnson (pictured in his Thame garden) last night sparked outrage by saying Theresa May’s Brexit strategy had put Britain in a suicide vest and given detonator to Brussels

It was also revealed that Ms Wheeler could be serving divorce papers branding him an 'adulterer' as early as Monday.

A source told The Sun she is looking to move on quickly as she has 'had enough.'

They said: 'The papers are coming imminently. They were due within the next fortnight but Marina’s just had enough.'

It comes as Mr Johnson was pictured looking glum in the garden of his Oxfordshire home with his head in his hands as he sipped a cup of tea.

Yesterday the MP faced fresh revelations about his relationship with Carrie Symonds, who abruptly quit as Tory communications director last month.

Sources last night claimed the pair had been on a series of high-class dates in London - including at the discreet Rosewood Hotel in Holborn.

With the Conservatives descending into open warfare, allies of Mr Johnson hit back, accusing No 10 of orchestrating a smear campaign with the leak of a ‘dirty dossier’ on his love life.

But Foreign Office minister Alan Duncan, who served as Mr Johnson’s deputy, yesterday described him as an ‘irresponsible wrecker’ and vowed to stop him becoming party leader.

Sarah Wollaston, Tory chairman of the Commons health committee, yesterday became the fourth MP to warn publicly that she would resign from the party if Mr Johnson toppled Mrs May.

A senior Tory said 12 or more MPs would refuse to serve under the former foreign secretary – effectively depriving the Government of a majority.

Mr Johnson’s critics accused him of using disgusting language to distract attention from his private life (pictured, former Tory aide Carrie Symonds)

‘Boris will never be prime minister – he would split the party,’ the MP said. ‘There are a large number of us determined to make sure he does not get onto the ballot paper whenever the leadership contest takes place.

‘If he did somehow manage to win then there are many of us – well into double figures – who would resign the party whip. He would lose the Government’s majority. He could not govern.’

The row came as:

Downing Street faced questions about whether Miss Symonds had been forced out of her job because of revelations about her closeness to Mr Johnson;

Jeremy Hunt, Sajid Javid and International Development Secretary Penny Mordaunt paraded their pro-Brexit credentials amid talk of a leadership contest;

David Davis prepared to unveil an alternative Brexit plan based on a technological solution to the Northern Ireland border issue;

No 10 launched a fresh charm offensive with MPs in a bid to win support for Mrs May’s Chequers plan;

Tory MP Nadine Dorries, an ally of Mr Johnson, said Miss Symonds appeared to have become ‘collateral damage’ in Downing Street’s war with him. Mr Johnson had been on the back foot following revelations last week that his 25-year marriage to Miss Wheeler was over. But yesterday he went on the attack with an incendiary article in which he renewed his criticism of the Prime Minister’s handling of Brexit.

Writing in the Mail on Sunday, he said Mrs May had allowed the Northern Ireland issue to become ‘grossly inflated’.

Yesterday he faced fresh revelations about his relationship with Carrie Symonds (pictured), who abruptly quit as Tory Party communications director last month.

It has now been suggested that Miss Symonds (pictured right with Michael Gove) may have lost her job for being too close to Johnson

He warned Brexit would fail unless she tore up the so-called ‘backstop’ agreed with the EU last December, which would keep Northern Ireland in the customs union. Mr Johnson described the Chequers plan, which would require Britain to follow a common rulebook with the EU, as a humiliation.

‘We look like a seven-stone weakling being comically bent out of shape by a 500lb gorilla,’ he said. ‘We have opened ourselves to perpetual political blackmail.

‘We have wrapped a suicide vest around the British constitution – and handed the detonator to Michel Barnier.’ Tom Tugendhat, chairman of the Commons foreign affairs committee, savaged Mr Johnson’s intervention and told him to grow up.

‘A suicide bomber murdered many in the courtyard of my office in Helmand,’ said the former Army officer. ‘The carnage was disgusting, limbs and flesh hanging from trees and bushes.

It comes after his wife Marina (pictured) began divorce proceedings when rumours of an affair surfaced

‘Brave men who stopped him killing me and others died in horrific pain. Some need to grow up. Comparing the PM to that isn’t funny.’

Sir Alan said: ‘For Boris to say that the PM’s view is like that of a suicide bomber is too much. This marks one of the most disgusting moments in modern British politics. I’m sorry, but this is the political end of Boris Johnson. If it isn’t now, I will make sure it is later.’

Alistair Burt, who also served under Mr Johnson, said there was ‘no justification for such an outrageous, inappropriate and hurtful analogy’.

Home Secretary Mr Javid urged Mr Johnson to use ‘measured language in future’, adding: ‘There are much better ways to articulate your differences.’

But allies of Mr Johnson rallied to his defence. MP Zac Goldsmith said there were ‘a number of possible motives’ for Sir Alan’s attack but ‘given its author, we can be certain principles aren’t one of them’.

Mrs Dorries said Mr Johnson faced vitriol because rivals were terrified of his popular appeal.

Ross Thomson, another Eurosceptic Tory, accused No 10 of trying to smear Mr Johnson, following the leak of a ‘black book’ on him.

Drawn up by a member of Mrs May’s team during the 2016 leadership election, the 4,000-word dossier details Mr Johnson’s affairs with journalists Petronella Wyatt and Anna Fazackerly and socialite Helen Macintyre, with whom he had a love child.

It also details his sacking by former Tory leader Michael Howard for lying, his admission that he tried cocaine at university and his controversial comments during years of column writing.

Mr Thomson said: ‘What on earth are No 10 playing at? We are all Conservatives. This is gutter politics that only serves to deliver the disaster of a Corbyn government.’

Downing Street sources angrily denied that they were involved in the leaking of the document to the media.