The last four runners in the Conservative leadership contest will face another round of voting later, as the party decides who will replace Boris Johnson in Downing Street.
But as the prospective leaders vie for the support of their fellow Tory MPs, their outgoing boss will hold his final cabinet meeting in Number 10.
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Mr Johnson is expected to discuss the heatwave with his ministers – after he faced criticism for missing three emergency COBRA meetings on the matter in recent days – as well as marking the anniversary of England coming out of COVID measures.
He is expected to say: “One year on from a successful reopening, we can reflect on what our brilliant NHS and country and has achieved, and we should be proud of how far we have come.
“Without our excellent scientists and clinicians, and everyone who came forward for their vaccine, we would have been in for a longer and bumpier road.”
Mr Johnson will host the cabinet meeting after his administration survived a confidence motion, which the government brought against itself after rejecting a Labour attempt to do so.
As the PM chairs his final cabinet meeting, Nadhim Zahawi will deliver his first speech as chancellor in the City. How much policy he is able to lay out is unclear, given the uncertainty surrounding his future in the job.
The remaining candidates to replace the PM were due to take part in a Sky News debate this evening, but it was cancelled after Mr Sunak and Ms Truss refused to participate.
They have no choice about facing the ballot, though, which will see the leadership hopeful with the lowest number of votes eliminated from the contest.
Former chancellor Mr Sunak continued to lead the pack last night by securing 115 votes in the third round, while Ms Mordaunt remained in second place with 82 votes.
Foreign Secretary Ms Truss won the support of 71 MPs, Ms Badenoch had the backing of 58, and Mr Tugendhat, who chairs the foreign affairs committee, received just 31 votes.
The candidates will now be hoping to win over Team Tugendhat and edge their numbers up in the fourth round of voting, with a result expected at 3pm – cutting another candidate from the field.
The last three will face one more ballot on Wednesday, with the final two confirmed by the end of the day.
The pair will carry out hustings over the summer before a vote by the wider party membership, and the final result is expected to be announced on 5 September.