Boris Johnson, one of the biggest voices in the Brexit movement, won the Conservative Party leadership race on Tuesday and will become the U.K.'s next prime minister.
Johnson, 55, was elected as his party leader, and consequently the U.K. leader, with 92,153 votes from members of the ruling Conservative Party. Foreign Minister Jeremy Hunt received 46,656 votes. Johnson will take up office on Wednesday.
President Donald Trump, who has publicly backed Johnson on several occasions during the leadership race, congratulated him via Twitter saying: "He will be great!"
The new prime minister, who has previously been foreign minister and mayor of London, will likely usher in a new team of ministers. Some incumbents have already announced their impending departure, including Finance Minister Philip Hammond, largely because of their different stances over Brexit. In addition to Brexit, Johnson faces an immediate crisis with with Iran, which seized a British oil tanker on Friday.
Speaking in front of party members after the announcement on Tuesday, Johnson said he would unite Britain.
"Like some slumbering giant we are going to rise and ping off the guy-ropes of self-doubt and negativity with better education, better infrastructure, more police, fantastic full-fiber broadband sprouting in every household. We are going to unite this amazing country and we are going to take it forward," he told the audience.
"I know that there will be people around the place who will question the wisdom of your decision and there may be some people here who still wonder what they have done, and I will just point out to you that no one party, no party has a monopoly of wisdom."
The leadership contest took place after Theresa May announced she would resign as prime minister following repeated rejections of the Brexit deal she struck with the EU last year.
How Johnson will proceed with Brexit now will be an immediate focus, given an impending deadline to leave the bloc of Oct. 31, and still no deal agreed upon by the U.K. parliament.
Johnson is infamous for his off-the-cuff remarks and somewhat eccentric character, and he has long been an influential and outspoken member of the Conservative Party. His decision to support the "Leave" vote ahead of the U.K.'s referendum on EU membership in June 2016 was seen as having a decisive effect on the result.
Since then, Johnson has made more controversial remarks over Brexit; most recently insisting that the U.K. must leave the EU on Oct. 31 "do or die, come what may" despite widespread concern over what a "no-deal" departure could mean for U.K. businesses and the economy.
Leaving without a deal with the EU would mean there is no transition period for the country to get used to life outside the EU's trading bloc. Trade and transport links between the EU and U.K. could therefore be severely affected.
Johnson also got into hot water in recent weeks for his apparent reluctance to support the U.K.'s ambassador to the U.S. following a leak of secret memos criticizing the Trump administration.
Following the announcement of Johnson's victory on Tuesday, U.K. opposition leader Jeremy Corbyn tweeted that Johnson had only won the support of fewer than 100,000 Conservative Party members by "promising tax cuts for the richest, presenting himself as the bankers' friend, and pushing for a damaging no-deal Brexit."