Sunak and Truss now take their case to Conservative party members, who will decide the new leader and prime minister after a dozen nationwide hustings and several televised debates over the next six weeks.
The result will be announced on September 5. But Britain is already guaranteed to get either its first prime minister of colour or its third woman leader.
“We need to restore trust, rebuild the economy, and reunite our country,” Sunak said after his win, as Britain contends with the worst cost-of-living crisis in decades, wrought by the pandemic, the war in Ukraine and Brexit.
Truss, the bookies’ favourite to beat Sunak based on recent polls of party members, said she was “not complacent at all”.
“What I believe is that lowering taxes, opening up opportunities, is going to help us deliver the economic growth that Britain needs,” she said.
“And it’s also going to help deliver us the next election.”
‘Hasta la vista’
At his last Prime Minister’s Questions session in parliament earlier, Johnson bowed out by saying “Hasta la vista, baby!”.
In a hint of support for Truss’s Thatcherite platform, he urged his successor to “cut taxes and deregulate where you can to make this the greatest place to live and invest”.
Johnson urged the contenders to continue his outspoken backing for Ukraine, and “stay close to the Americans”.
Mordaunt — the one-time bookmakers’ favourite — lapsed to outsider status after Truss’s fellow right-winger Kemi Badenoch was eliminated Tuesday.
Former minister David Davis, a Mordaunt backer, accused Sunak of lending Truss votes so he could face her in the run-off.
“He wants to fight Liz, because she’s the person who will lose the debate with him,” he told LBC radio.
A YouGov poll published before the vote indicated that, despite his popularity with colleagues, Sunak was the least appealing candidate to the members.
The BBC and Sky News both plan to host live TV debates between the pair, the first on Monday, with other potential duels possible before party members’ postal voting ends September 2.
Sunak won the two previous debates, according to snap polls, and the second one featured a no-holds-barred clash with Truss.
The dozen hustings in front of the membership — the first in Leeds, northern England, next Thursday — will take the candidates to all corners of Britain, including Scotland, Wales and Northern Ireland.
The Conservatives have declined to say how many eligible members they have, but have noted it will be more than the 160,000 who voted at the last leadership contest in 2019.
Sunak’s popularity with the grassroots has faded since questions were raised over his family’s tax arrangements, and as he presided over sky-rocketing inflation, which hit a new 40-year high of 9.4 percent in June.
In a new policy announcement, Sunak vowed an “ambitious new plan to make the UK energy independent” by 2045 to prevent future energy-driven inflation spikes, after Russia’s war in Ukraine sent gas prices rocketing.
Meanwhile, Truss has pledged a host of tax cuts “from day one”.
Johnson announced on July 7 he was quitting as Conservative leader after a government rebellion in protest at his scandal-hit administration.
Under Britain’s parliamentary system, the leader of the biggest party is prime minister and can be changed mid-term without having to call a general election.
Labour’s Starmer accused the Tory candidates of “fantasy economics” before turning his fire on the outgoing Johnson.