Boris Johnson warned Tory MPs will back vote of no-confidence to block no-deal Brexit

Boris Johnson has been warned that as many as a dozen Conservative MPs will back a vote of no-confidence, triggering a general election, to block a no-deal Brexit.

The former foreign secretary has promised to take the UK out of the EU on 31 October with or without agreement on divorce terms. And his rival for the Tory leadership Jeremy Hunt has not ruled out a potentially damaging no-deal outcome, though he says he is ready to extend Brexit negotiations in the hope of avoiding it.

With the incoming prime minister likely to have a working majority of no more than three MPs in the House of Commons when he arrives at 10 Downing Street next month, defence minister Tobias Ellwood left no doubt that opponents of no-deal believe they have the numbers to stop the UK crashing out.

"I think a dozen or so members of Parliament would be on our side, would be voting against supporting a no deal, and that would include ministers as well as backbenchers," he told BBC1’s Panorama: The Race for Number 10.

Tory grandee Kenneth Clarke, a veteran of Margaret Thatcher’s governments, said he would not rule out joining a no-confidence rebellion, insisting: “I am not going to vote in favour of a government that says it is going to pursue policies which are totally incompatible with everything the Conservative Party has stood for under all those prime ministers for the decades that I have been in Parliament."

And Mr Hunt suggested that the coalition of hard Brexiteers and moderates which carried Mr Johnson to overwhelming victory in the Westminster phase of the leadership race last week will “collapse” swiftly if the former London mayor reaches office.

"Sometimes in politics you can fudge and get away with it but in the case of Brexit you are going to have to make decisions immediately, and that very fragile coalition will collapse immediately when you have to make those decisions,” Mr Hunt told Radio 4’s Today.

"If that happens we won't have another leadership contest, we will have Jeremy Corbyn in No 10 and there won't be any Brexit at all."

The warnings came as controversy raged over Mr Johnson “bottling” debate as the four-week campaign for the votes of 160,000 Conservative members gets under way.

Mr Hunt told his rival not to be a coward and to “man up” and face him in head-to-head TV debates, as Sky News cancelled a showdown planned for Tuesday when Mr Johnson declined to sign up.

The foreign secretary branded his opponent “very disrespectful” for refusing to take part in debates before ballot papers are sent out to Tory members on 6 July, when many are expected to immediately cast their votes.

"The way to earn that trust with Conservative Party members and with the country is to subject yourself to scrutiny, to answer questions about what you actually want to do," said Mr Hunt.

But the Johnson camp insisted their candidate was undergoing “a huge amount of scrutiny”, with 16 hustings events around the country and three televised debates – one during a series of MPs’ votes last week and two more in the final weeks before ballots close on 22 July.

Insisting that Mr Johnson was “looking forward” to debating policy with Mr Hunt, a source said: “We would like to get our message out to the biggest possible audience, which is why we have chosen ITV over Sky.”

Johnson supporters came to his defence over the noisy altercation which led to police attending the London flat he shares with partner Carrie Symonds in the early hours of Friday.

MP Nadine Dorries said Mr Johnson and Ms Symonds were “together, strong and united” and she was “stunned at the level of harassment they have had to endure, while Jacob Rees-Mogg denounced the concerned neighbours who recorded the pair’s argument as “Corbynista curtain-twitchers”.

But eyebrows were raised at photographs obtained by the MailOnline website which supposedly showed the couple holding hands and smiling in a rural setting on Sunday. Johnson spokespeople were unable to say when the pictures were taken, and social media sceptics pointed out that Mr Johnson’s hair appeared significantly longer than when he was snapped on Saturday.

The Johnson camp said the leadership frontrunner would be stepping up media appearances as his drive for members’ support gets under way in earnest in the coming days, with five campaign events due to take place in London and Surrey on Tuesday.

Mr Johnson came under assault from Mr Clarke as “quite the most hopelessly irresponsible foreign secretary I’ve ever known from any party.”

The long-serving cabinet minister told Panorama that Mr Johnson was “a disaster” at the Foreign Office, driving diplomats “up the wall” and making “appalling gaffes”>

And Theresa May’s effective deputy PM David Lidington said Mr Hunt would be “better equipped” to deal with national security emergencies.

Speaking during a visit to Scotland, Mr Lidington said: "The prime minister will have to take those decisions often under severe time pressure and almost inevitably on the basis of intelligence evidence that is, by its very nature, going to be incomplete.

"My judgement is that Jeremy is the one who is best equipped to deal with the 3am call.”

A source in the Johnson team retorted: “Boris is the most experienced candidate in this election, with a track record of making the big calls, working with international partners, handling major events and cutting crime.”

Johnson supporter Johnny Mercer acknowledged that the Brexit figurehead came with “his own risks that others will not have”.

But he added: “We have to put a premium on a) winning elections, b) delivering things for people who vote for us. And I think the best way of doing that at the moment is to try and shape a Boris Johnson premiership.”