Foreign Secretary Liz Truss has overtaken Penny Mordaunt to become one of the final two in the Tory leadership race.
Truss came second in Wednesday afternoon's final ballot of Conservative MPs with 113 votes, compared to Trade Policy Minister Mordaunt's 105.
She will join former chancellor of the exchequer Rishi Sunak, who increased his support from 118 votes on Tuesday to 137, on the ballot papers to be sent out to party members for voting over the next six weeks during the Parliamentary summer recess.
Truss promised to "hit the ground running from day one" if elected.
"I am excited to now take to the country to make the case to the Conservative Party about my bold new economic plan that will cut taxes, grow our economy and unleash the potential of everyone in our United Kingdom".
Sunak tweeted a video thanking his supporters, adding: "We need to restore trust, rebuild the economy and reunite our country".
Mordaunt praised her rivals and urged fellow MPs to "work together to unify our party" after the contentious campaign.
"Politics isn't easy. It can be a divisive and difficult place. We must all now work together to unify our party and focus on the job that needs to be done," she said. "I am a One Nation, proud Brexiteer. My campaign put forward a positive vision for the country I love so much, remembering who we are here to serve."
Truss gained 27 votes following former equalities minister Kemi Badenoch's exit from the contest on Tuesday, while Mordaunt only managed to increase her tally by 13. Badenoch was seen as the most conservative of the remaining candidates this week, especially on trans issues where Mordaunt was criticised for being too 'woke'.
While enjoying the support of more fellow MPs, Sunak is unpopular among the the roughly 200,000 grassroots party members for his tax rises — partly to pay for COVID-19 lockdown furlough payments to prevent workers from being made redundant — and for leading the wave of government resignations a fortnight ago that forced Prime Minister Boris Johnson to resign as party leader.
But Sunak's supporters point to a recent Ipsos Mori poll that concluded he was the best-placed candidate to lead the Tories to victory over opposition leader Sir Keir Starmer's Labour Party.
The son of Afro-Indian immigrants, married to the daughter of an Indian billionaire businessman, could soon become the first black British prime minister.
Truss has portrayed herself as a true blue Tory and the continuity candidate for Johnson's government, as well as the most hawkish towards Russia over its special military operation in the Ukraine.
But she is a former member of the Liberal Democrat Party whose parents were in the Campaign for Nuclear Disarmament, and she backed the Remain side in the 2016 European Union membership referendum.
Johnson will stay on as PM until the new leader is announced on September 5.