Three candidates are left in the contest to replace Boris Johnson as British prime minister.
Below are some details on the contenders, who are listed in alphabetical order.
PENNY MORDAUNT
The former defence secretary was sacked by Johnson after she endorsed his rival, Jeremy Hunt, during the 2019 leadership contest.
Mordaunt, 49, was a passionate supporter of leaving the EU and has said she will aim to deliver the benefits of Brexit and help Britain recover from economic shocks such as the pandemic.
Currently a junior trade minister, Mordaunt called the COVID lockdown-breaking parties in government "shameful" and has said that if she is prime minister, leadership has to change to be less about the leader.
RISHI SUNAK
In his campaign launch video, Sunak promised to confront the difficult economic backdrop with "honesty, seriousness and determination", rather than piling the burden onto future generations.
The 42-year-old became finance minister in early 2020 and was praised for a COVID economic rescue package, including a costly jobs retention programme that averted mass unemployment.
But he later faced criticism for not giving enough cost-of-living support to households. Revelations this year about his wealthy wife's non-domiciled tax status, and a fine he received for breaking COVID lockdown rules, have damaged his standing.
His tax-and-spend budget last year put Britain on course for its biggest tax burden since the 1950s, undermining his claims to favour lower taxes.
Sunak voted to leave the EU in the 2016 referendum.
LIZ TRUSS
The foreign secretary has been the darling of the Conservative Party's grassroots and has regularly topped polls of party members carried out by the website Conservative Home.
Truss has a carefully cultivated public image and was photographed in a tank last year, echoing a famous 1986 photo of former prime minister Margaret Thatcher.
She spent the first two years of Johnson's premiership as international trade secretary and is now in charge of dealing with the EU over post-Brexit trade rules for Northern Ireland, where she has taken an increasingly tough line in negotiations.
Truss, 46, initially campaigned against Brexit but after the 2016 referendum said she had changed her mind.
($1 = 0.7971 pound)
(Additional reporting by Alistair Smout; Editing by Alison Williams)
