Boris Johnson has launched his bid for the Tory crown with a warning to MPs that they will face “mortal retribution” from the electorate if they try to stop Brexit.

The former foreign secretary presented himself as the one candidate among the contenders bidding to succeed Theresa May who could stop Jeremy Corbyn seizing the keys to No 10.

But at a packed launch event in London, he said it was essential that Parliament now delivered on the 2016 referendum vote and that Britain left the EU, without a deal, on October 31.

His warning came as MPs opposed to a no-deal Brexit prepared to launch a fresh cross-party attempt to take control of the Commons agenda to prevent Britain leaving the EU in the autumn without a deal in place.

“I think maturity and a sense of duty will prevail. I think it will be very difficult for friends in Parliament to obstruct the will of the people and simply to block Brexit,” Mr Johnson said.

“I think if we now block it, collectively as parliamentarians we will reap the whirlwind and we will face mortal retribution from the electorate.”

Mr Johnson insisted he wanted a “sensible, orderly” departure from the EU but said the country had to be ready for a no-deal Brexit if it was to get the terms it needed from Brussels.

“It is only responsible to prepare vigorously and seriously for no-deal,” he said.

“The best way to avoid that is to prepare for it and be absolutely clear to our friends and partners that we are prepared to do that.”

He warned that failure to deliver on the referendum result would create an “existential threat” for both Labour and the Conservatives.

“Around the country there is a mood of disillusion, even despair, at our inability to get things done,” he said.

“After three years and two missed deadlines we must leave the EU on October 31.”

Boris Johnson said MPs will ‘reap the whirlwind’ if they try to block Brexit (Stefan Rousseau/PA)

Mr Johnson, who is the clear front-runner in the leadership race, had to fend off a series of reporters’ questions about his past character and record in office.

After Michael Gove’s admission that he had taken cocaine in the past, Mr Johnson sidestepped a question as to whether he had also used the drug.

He acknowledged that his use of language – such as his description of Muslim women who wore the burka as letter boxes – sometimes resulted in ”some plaster coming off the ceiling”.

However he rejected past charges of untrustworthiness levelled at him by colleagues and rivals.

Referring to his record as mayor of London, he said:  “I do what I promise to do as a politician.”

Tory leadership race
Boris Johnson’s brother Jo (left) and his father Stanley at his leadership launch (Stefan Rousseau/PA)

Meanwhile, there was anger among Brexiteers at the latest move by MPs opposed to no-deal to seize control of Commons business from the Government.

Labour is using an opposition day debate to try to give control of the Commons agenda to MPs on June 25 in order to stop the UK exiting the EU without a deal in the autumn.

Prominent Brexiteer Sir Bill Cash strongly attacked supporters of the move, who include Tory former minister Sir Oliver Letwin, plus the SNP, the Liberal Democrats, Plaid Cymru and the Greens.

Sir Bill told the Press Association: “They are causing a breakdown of our democracy.”

With the Labour-led motion only needing a relatively small number of Tory MPs to support it for success, Sir Bill, who supports Mr Johnson, was scathing about the involvement of Sir Oliver, who is backing Mr Gove in the leadership race.

Sir Bill said: “He has put his name to an opposition day motion with Marxist Jeremy Corbyn.”

Government sources said the motion would set an “uncomfortable and troubling precedent” and were clear that Tory MPs would be whipped to vote against it.

“There is an important constitutional principle here about governments having control of the order paper in order to deliver their business,” one source said.

However, Labour made clear that if the motion was defeated, the party would find other ways to prevent no-deal, including a possible vote of no confidence.

“No-deal cannot be imposed on the country or on Parliament and we will find mechanisms to make sure that doesn’t happen,” a senior party source said.

Shadow Brexit minister Jenny Chapman said the vote on blocking a no-deal Brexit was a “safety valve” aimed at Tory leadership contenders trying to freeze MPs out of the decision.

She told BBC Radio 4’s Today programme: “This is about that safety valve, that lock in the process, so that somebody who may find themselves elected a leader of the Tory Party on a promise of, in Dominic Raab’s case, proroguing Parliament, and locking Parliament out of this process – they can’t do that.

“They would have to come back to Parliament and get the consent of MPs.”