Tobias Ellwood said the rebels – including ministers – would opt for the “nuclear option” and risk a general election if it meant avoiding the UK crashing out of the European Union.
The stark warning echoes comments from Amber Rudd, the work and pensions secretary, who admitted earlier this month there were a sufficient number of Conservative MPs willing to take the extraordinary step.
So far, two senior Conservatives have publicly said they would consider voting against their own government, including Dominic Grieve, and the former minister Ken Clarke, to prevent “some idiot” pushing a no-deal scenario without the consent of the Commons.
On the possibility of some Conservative MPs supporting the “nuclear option” of denying the government Commons support, Mr Ellwood told the BBC: “I believe that absolutely is the case.
“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.”
If a government loses a no confidence motion in the Commons, there will be a 14-day period for parties at Westminster to form a viable government and pass a motion of confidence. If this route failed, a general election would be called.
The defence minister’s remarks came as Mr Johnson used his regular column in The Daily Telegraph to renew his commitment to leave the EUon 31 October, insisting “we can, we must and we will” leave on the promised date.
He faced criticism last week during a TV debate for appearing to water down his stance on the Brexit deadline, saying it was “eminently feasible” the UK could leave the bloc by the deadline.
But Mr Johnson writes today: “We are just over four months away from the date on which, by law, we must leave the EU: and this time we are not going to bottle it. We are not going to fail.
Mr Johnson’s rival in the race Jeremy Hunt claimed on Monday that a government under the former London mayor would rapidly collapse and pave the way for Labour to take power.
He is going to come to power on a very fragile coalition of people like Matt Hancock who wants no-deal taken off the table, Mark Francois who wants no-deal,” he told ITV’s Good Morning Britain.
“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.
“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.”