Tory MPs will cast their votes on Monday, in the third round of the contest to find a successor to Boris Johnson.
They will vote from 5pm, with chairman of the 1922 Committee Sir Graham Brady expected to announce the results at 8pm.
Once whittled down to four, there will be another round of voting on Tuesday – and, if no one pulls out, the leadership race will be reduced to two candidates by Wednesday.
The final two will then campaign for member votes, before a winner is confirmed in September.
The remaining candidates were involved in a series of fiery exchanges in the latest TV debate on Sunday evening.
Tory leadership race: Liz Truss, Rishi Sunak, Penny Mordaunt, Tom Tugendhat, Kemi Badenoch
UK Parliament
Ex-Chancellor Rishi Sunak, who topped both the first two ballots, clashed with international trade minister Penny Mordaunt and Foreign Secretary Liz Truss over the economy.
And former equalities minister Kemi Badenoch and Tom Tugendhat – who finished fourth and fifth in the last ballot – squared off over who had the record and experience to be prime minister.
Ms Truss will be hoping to pick up votes from Attorney General Suella Braverman who endorsed her candidacy after she was eliminated in the last round.
Despite having voted Remain in the 2016 referendum, the Foreign Secretary is backed by many Brexiteers while Ms Braverman is a longstanding supporter of leaving the EU.
Tory leadership contenders taking part in a live TV debate
Jonathan Hordle/ITV
The rivals faced off in a TV debate on Sunday
Jonathan Hordle/ITV
Unless a significant slice of the 27 MPs who voted for Ms Braverman last time now switch to her, Ms Truss’s hopes of overhauling Ms Mordaunt in second place may be slim.
The Foreign Secretary opened the debate in a combative mood, attacking Mr Sunak for putting up taxes to their highest level in 70 years.
Mr Sunak hit back, accusing her of peddling “something-for-nothing economics”, adding that “isn’t Conservative. It’s socialism”.
Later in the ITV debate, he asked her what past experience she regretted most – having been a Remainer or a Liberal Democrat.
Mr Sunak also clashed with Ms Mordaunt, saying her plan to relax the fiscal rules and “put day-to-day bills on the country’s credit card” was “not just wrong, it is dangerous”.
He added: “Even Jeremy Corbyn didn’t go that far."
There was more bad blood also between Ms Mordaunt and Ms Badenoch over the trade minister’s views on identity politics and trans issues.
In the first debate, Ms Badenoch accused her of having pushed a policy of self-identification for trans people seeking to legally change their gender – something Mr Mordaunt strongly denied.
After more claims in the press over the weekend, Ms Mordaunt said: “I know why this is being done but I would say all attempts to paint me as an out of touch individual will fail.”
Ms Badenoch repeatedly tried to interrupt, saying: “Penny, I was just telling the truth. I am telling the truth.”
Despite only having finished fourth in the last ballot, there are signs Ms Badenoch is picking up support among Tory activists and her supporters hope it will persuade more MPs to vote for her, giving her a chance of making it into the final two.
Ms Badenoch hit back at Mr Tugendhat – the only candidate who has not been a minister – when he suggested those who had served under Mr Johnson had lent “credibility to chaos” and would find it harder to overcome Labour in a general election.
Ms Badenoch said she was “not ashamed of anything we did”, and that serving as a minister requires difficult decisions.
She added: “Tom has never done that. It’s very easy for him to criticise what we’ve been doing, but we have been out there on the front line making the case."
Mr Tugendhat retorted that, as a former army officer, he had been on the front line in Afghanistan and Iraq and had led “in the argument against Putin and China”.
The Tory leadership debate on Sky News planned for Tuesday night has been cancelled.
