Who will be the next British PM? A look at the contenders to replace Liz Truss

After Boris Johnson ruled himself out of the Conservative Party leadership race, two candidates have emerged as front-runners to replace Liz Truss as British prime minister — and to try to salvage the scandal-ridden Tory government.

Former Treasury chief, House of Commons leader considered credible contenders; Boris Johnson rules himself out

Penny Mordaunt and Rishi Sunak appear to be the final two contenders for the Conservative Party leadership. Here, they appear at a live television debate in London during their previous bids for the party leadership in July. (Victoria Jones/PA/The Associated Press)

It appears there are just two contenders left in the running to become the next British Prime Minister, three days after Liz Truss's resignation triggered another leadership race — the second in just four months — for the U.K.'s fractured and demoralized Conservative Party.

Truss, who quit after just 45 days in office, said her successor will be chosen in a leadership contest to be completed by Oct. 28. Whoever wins will become the fifth British prime minister in six years.

Under hastily improvised rules released by the Conservative Party on Thursday, each leadership candidate will require the support of at least 100 MPs to even qualify for the race.

With 357 sitting members of Parliament, that means there could be a maximum of three candidates for party members to vote on. However, if only one candidate meets the threshold by a 2 p.m. Monday deadline, then that person would automatically be selected as the new leader and the new prime minister.

Here's a look at the potential contenders:

Rishi Sunak, former Treasury chief

Rishi Sunak leaves his home in London on July 9 after launching his campaign to be the next leader of the Conservative Party following Boris Johnson's resignation. (Hollie Adams/Getty Images)

Sunak, who came second to Truss in the last Conservative leadership race, now has the backing of at least 124 Conservative lawmakers, according to unofficial tallies compiled by British news organizations. That's well ahead of the 100 nominations required to qualify for the leadership.

The 42-year-old quit as Treasury chief in July, in protest against then-Prime Minister Boris Johnson's leadership. In the contest to replace Johnson, he argued that climbing inflation must be controlled first, and called promises by Truss and other rivals to immediately slash taxes reckless "fairy tales."

Sunak was proved right when Truss's unfunded tax-cutting economic stimulus package tanked the British pound and triggered chaos in the markets in September.

Sunak became Treasury chief in 2020 and steered Britain's slumping economy through the coronavirus pandemic. He oversaw billions of pounds in government handouts to help businesses and workers hard hit by COVID-19. In the past year, he faced heavy criticism for being slow to respond to Britain's cost-of-living crisis.

Born to Indian parents who moved to Britain from East Africa, Sunak attended England's exclusive Winchester College private school and studied at Oxford. Some see his elite education and work for the investment bank Goldman Sachs and a hedge fund as a liability because it makes him seem out of touch with ordinary voters.

Penny Mordaunt, House of Commons leader

House of Commons leader Penny Mordaunt arrives on Day 2 of the annual Conservative Party conference in Birmingham, England, on Oct. 3. (Leon Neal/Getty Images)

Mordaunt, 49, came third after Sunak and Truss in the last Tory leadership race. As of Sunday, Mordaunt had support from about 23 MPs to become the next leader, according to British media outlets' unofficial tallies. 

Mordaunt did not hold a senior post in Johnson's cabinet, and previously positioned herself as offering a clean break from his scandal-tainted government.

A former international trade minister, Mordaunt is popular among Conservative legislators. Some believe she could be the right candidate to help heal the party's divisions. But she is largely an unknown figure to most Britons, and outside Conservative circles she remains best known for appearing on the 2014 reality TV show Splash!

Mordaunt played a prominent role in the pro-Brexit campaign. She was the first woman to become British defence secretary in 2019 — though she was removed by Johnson after just three months in the post because she had backed another candidate for party leader, Jeremy Hunt.

Who's out of the race?

Truss's predecessor Boris Johnson ruled himself out of the leadership race Sunday, despite support from many Conservative MPs — just weeks after he was forced out of office by a series of ethics scandals.

Johnson had spent the weekend trying to gain support from fellow lawmakers after flying back from a Caribbean vacation. Late Sunday, he said he had amassed 102 names, reaching the threshold to run, but conceded he was far behind Sunak in support.

Former British Prime Minister Boris Johnson ruled himself out of the leadership race Sunday. Here, he's pictured during his farewell address at 10 Downing Street, London, before his official leadership resignation on Sept. 6. (Leon Neal/Getty Images)

Defence Secretary Ben Wallace, a 52-year-old army veteran, on Friday said he would not stand for the leadership. At the time, he said he was leaning toward supporting Johnson.

Suella Braverman, who resigned as home secretary late Wednesday with a scathing letter criticizing Truss's "tumultuous" premiership, had been tipped as a possible candidate, but endorsed Sunak on Sunday in an op-ed for The Telegraph.

"We are in dire straits now. We need unity, stability and efficiency. Rishi is the only candidate that fits the bill and I am proud to support him," she wrote.