Former UK Chancellor Rishi Sunak and current Foreign Secretary Liz Truss will face each other in a runoff vote to replace Prime Minister Boris Johnson.
The ruling Conservative party chose Sunak and Truss for the election after a vote on Wednesday. Trade Minister Penny Mordaunt narrowly came in third and was eliminated.
The result came on the same day that the UK's scandal-ridden leader concluded his final Prime Minister's Questions.
Johnson, who announced his resignation on 7 July, rounded off his final appearance at the dispatch box with a famous catchphrase from The Terminator.
He also praised his own self-perceived accomplishments in delivering Brexit, leading the UK through the COVID pandemic, and supporting Ukraine against the Russian invasion.
"Mission largely accomplished, for now," Johnson told MPs. "I want to thank all the wonderful staff at the House of Commons, I want to thank all my friends and colleagues."
"I want to thank everybody here, and hasta la vista, baby," he added as Conservative MPs gave him a standing ovation.
The race to Number 10 Downing Street now pits Sunak, who steered Britain’s economy through the pandemic, against Truss, who has led the UK’s response to the Ukraine war.
Sunak has won every round of voting by lawmakers but is less popular with the party’s grassroots. Truss meanwhile is a favourite of the party’s right wing.
The two contenders will spend the next few weeks campaigning for the votes of about 180,000 Conservative Party members around the country, who will vote by postal or online ballot.
The winner of the party leadership vote will be announced on September 5, and will automatically become Britain’s next prime minister.
The bitter campaign has so far exposed divisions in the Conservative Party following Johnson’s three-year reign.
Opponents have branded Sunak a “socialist” for raising taxes in response to the economic damage wrought by the coronavirus pandemic and the Ukraine war, with the former chancellor of the exchequer hitting back that his rivals are peddling economic “fairy tales.”
The contenders are all trying to distance themselves from Johnson, whose term in office began boldly in 2019 with a vow to “get Brexit done” and a resounding election victory.
Johnson remained in office through months of controversy surrounding his finances and his judgment, refusing to resign when he was fined by police over drunken parties during the COVID-19 lockdowns.
He finally quit after another scandal — appointing a politician accused of sexual misconduct — which drove his ministers to resign en masse.
Despite remaining prime minister, Johnson has largely stepped back from the public eye, even as the UK faces a summer cost-of-living crisis and labour discontent as inflation hits 9.4%.
Johnson did not attend any government emergency meetings about the heat wave that brought temperatures of 40 degrees Celcius to the UK this week.
Last week he took a ride in a Royal Air Force Typhoon fighter jet, with “Top Gun”-style footage released by his office, then threw a weekend party at Chequers, the country house that comes with the prime minister’s job.
London Mayor Sadiq Khan, who represents the opposition Labour Party, accused Johnson of wanting to “become Tom Cruise” and urged him to resign immediately.
“We need a full-time prime minister looking after our country rather than somebody who’s checked out,” Khan said.
It was a downbeat departure for Johnson, with supportive Conservative backbenchers lobbing praise and opposition politicians offering variations on "good riddance."
Labour Party leader Keir Starmer said: “I will miss the delusion.”