Boris Johnson has overwhelmingly won the first round of voting Thursday in the race to replace outgoing British Prime Minister Theresa May, with the field of candidates narrowed to seven from 10.
The Brexit-backing former foreign minister picked up 114 of the 313 votes cast in a secret ballot of Conservative Party lawmakers in the lower House of Commons.
Three ministers failed to meet the threshold of 17 votes needed to stay in the race.
Seven contenders remain in the contest to succeed Theresa May as party leader and prime minister.
Further elimination votes will be held next week, with the final two contenders put to a vote of 160,000 Conservative Party members across the country.
The result is expected in late July.
Ms May, who remains prime minister, stepped down as the centre-right party's leader on Friday, having failed to deliver her plan for taking Britain out of the European Union after nearly three years in the post.
Bookmakers have ex-foreign secretary Boris Johnson as their odds-on favourite to win the contest to replace her.
The former London mayor launched his campaign on Wednesday, saying he would only take Britain out of the EU without a deal as a "last resort" as he promised to unify a country deeply divided over Brexit.
UK leadership contenders Source: AAP
A cross-party effort to block a chaotic end to the 46-year partnership failed on Wednesday, potentially leaving more room for maneuver for a future premier.
Parliament may now have run out of options to block a no-deal Brexit by the next PM, admitted Oliver Letwin, one of the plan's architects.
"I have really struggled very hard to think of every available opportunity and I can't currently think of any more," the Conservative MP told BBC radio on Thursday.
Mr Johnson said that if parliament blocks Brexit completely, "we will reap the whirlwind and we will face mortal retribution from the electorate".
Drugs and backbiting
Foreign Secretary Jeremy Hunt is considered Mr Johnson's closest challenger.
Interior minister Sajid Javid, Environment Secretary Michael Gove and former Brexit secretary Dominic Raab also have enough publicly-declared backers to make it through to the second round.
The contest so far has been dominated by revelations of past drug-taking by candidates and bickering over the best way to resolve the Brexit impasse.
On the left, Theresa May on the day she became British prime minister and on the right, May pictured on 24 May, 2019 when she announced her resignation. Source: AAP
But Thursday's voting will reveal each candidate's current level of support.
The ballot takes place in a Houses of Parliament committee room between 10am and 12pm, with the results expected to be announced around an hour later.
Former pensions secretary Esther McVey and ex-immigration minister Mark Harper are considered the most vulnerable.
Ms McVey is pursuing a no-deal Brexit, arguing that the agreement struck by Ms May keeps Britain too closely tied to the EU.
Mr Harper said an extension would be needed beyond the 31 October deadline to secure a deal.
Health Secretary Matt Hancock, who is against no-deal, may have enough votes to scrape through.
"We've got to deliver Brexit; but then we've got to win a majority by appealing to aspirational people in the centre ground of British politics, where there's a gaping hole," he told The Guardian newspaper.
TV test
Former House of Commons leader Andrea Leadsom, a managed no-deal supporter, told ITV television she was "very optimistic" of having enough votes to get through.
Meanwhile, International Development Secretary Rory Stewart, the contender most vehemently against leaving the EU without a deal, told The Sun newspaper he feared he was still "one or two votes short".
The survivors face their first live television debate on Sunday in a 90-minute program on Channel 4.
They have another round of hustings before Conservative MPs on Monday before Tuesday's second ballot, when the bar rises from 16 backers to 32, again with the contender with the fewest votes dropping out.
After further rounds of voting next week, the party hopes to be down to the last two by the end of 20 June.
After weeks of hustings around the country, the 160,000 grass-roots Conservative party members pick the winner, with the result announced in the week beginning 22 July.
Ms May will then step down as prime minister and the new leader of the largest party in parliament will be appointed as PM by Queen Elizabeth II.
