Boris Johnson is Britain’s new prime minister after winning the Conservative leadership election by a landslide.

The Uxbridge and South Ruislip MP beat rival Jeremy Hunt, his successor as foreign secretary, by 92,153 votes to 46,656 after a seven-week contest, involving 16 hustings, around the UK.

The former mayor of London once famously said: “My chances of being PM are about as good as the chances of finding Elvis on Mars, or my being reincarnated as an olive.”

But he moves into Downing Street at a time of political crisis, with Brexit his most pressing concern.

Johnson, 55, has promised to seek a new deal with the EU or leave without an agreement at the end of October.

But that sets him on a collision course with several major figures within his party – chancellor Philip Hammond, international development secretary Rory Stewart and justice secretary David Gauke will all step down rather than deliver Johnson’s Brexit agenda.

Just minutes before the announcement, education minister Anne Milton resigned while Johnson’s one-time Foreign Office colleague Alan Duncan quit as a minister on Monday and unsuccessfully tried to lay a motion to test his slender two-seat majority before he even takes office.

Meanwhile, other Tory rebels – including former Attorney General Dominic Grieve – have threatened to vote down his fledgling government if Johnson pushes a hardline in his negotiations with Europe.

However, the new prime minister, who will formally succeed Theresa May on Wednesday, tried to strike a note of conciliation and optimism.

"I read in my Financial Times this morning that no incoming leader has ever faced such a daunting set of circumstances," said Johnson.

"I ask myself - do you look daunted? Do you feel daunted? I don't think you look remotely daunted to me. I know we can do this and the people of this country are trusting in us to do it.

"We will get Brexit done by October 31st and take advantages of all the opportunities it will bring in a new spirit of 'can do'.

"We will believe in ourselves and what we are going to achieve. Like a slumbering giant we are going to rise and ping off the guy ropes of self-doubt and negativity."

On a local level, Johnson will have a major say in the controversial future development of Heathrow.

He has previously voiced his opposition to expansion of the airport, famously declaring that he would ‘lie in front of the bulldozers’.

However, after parliament voted by nearly four to one to agree to Heathrow’s third runaway, he softened this stance, insisting he would monitor the legal cases on air and noise pollution.

But Rob Barnstone, coordinator of Stop Heathrow Expansion, believes Johnson could still intervene.

“Boris Johnson knows that Heathrow expansion cannot meet environmental targets, including on noise and air pollution,” he said.

“He has indicated that he will be following the legal and planning processes very carefully – so at the appropriate time, the project can be cancelled.

“We don’t expect any gimmicks, but remain confident that Mr Johnson will stop this disastrous project, albeit at the correct time in the process.”

Johnson’s immediate concern will be appointing a new cabinet that delivers on his talk of consensus, including what to do with fellow Brexiteer and arch-rival Michael Gove. He will address Conservative backbenchers in Westminster tonight.

Aside from the numerous twists and turns in Brexit politics, tensions in the Gulf and the huge budget overrun in high-speed rail – a project Johnson has been lukewarm in support of – will be high in his new in-tray.