Who will be next UK PM? Rishi Sunak vs Tom Tugendhat - Race heats up!

The hottest day in history may be over but the heat of the Conservative Party leadership battle intensified on Wednesday as Tory lawmakers cast their last round of votes to determine the final two candidates in the race to replace Boris Johnson as British Prime Minister.

Rishi Sunak is holding firm as the frontrunner with 118 votes from Tuesday's secret ballot, but the fact that he gained just three votes from Tom Tugendhat's camp after the Tory backbencher's elimination has triggered intense speculation over tactical voting and even rigging.

While the British Indian former Chancellor is almost confirmed as one of the final two candidates, the battle for second spot between Trade Minister Penny Mordaunt and Foreign Secretary Liz Truss has become increasingly heated as questions arise over how the latter gained 15 more votes to hit 86.

In contrast, Mordaunt increased her tally by 10 to hold on to second place with 92 votes.

"There is vote-rigging going on. There is no way that Truss picked up 15 votes from Tom Tugendhat. Someone is moving votes around," one baffled Tory MP told The Daily Telegraph newspaper.

"Rishi only went up by three votes. That does not make any sense. They want Rishi versus Liz," the MP said.

A leading pro-Sunak MP admitted to the newspaper that it was "entirely possible" that individual MPs had acted on their own initiative, but there was no central direction from Sunak.

"It's entirely possible that individual members of Parliament have chosen to do things for their own outcomes, but as a campaign we've been very clear that we've encouraged every colleague that wants Rishi to win to vote for him. Colleagues have been lobbied very hard to vote for other people on a 'lend me your vote' basis. We haven't been doing that," the MP said.

David Davis, a former Brexit minister and Mordaunt supporter, claimed that the Sunak camp had reallocated votes from Tugendhat to Truss to stop the trade minister reaching the final two as the Foreign Secretary's economic plans are seen as easier to counter for the former finance minister.

"Some [votes] went to Liz Truss. There's no doubt about it... I think about [10], maybe a few more, went to Rishi and then Rishi just reallocated some. He wants to fight Liz, because she's the person who will lose the debate with him," Davis told LBC.

Such claims of so-called vote lending were officially denied by Sunak's camp, with a spokesperson saying: "We haven't lent any votes, we are going for every single vote, as you can see, it's close."

The Truss and Mordaunt camps clashed in favour of their candidate as the most qualified to face the ballot of Conservative Party members to determine the final outcome by September 5.

Simon Clarke, the Chief Secretary to the Treasury, suggested Mordaunt has limited Cabinet experience and would not be ready to govern "on day one".

This was met with backlash from the rival camp, which insisted Mordaunt had "set out more of her vision than anyone else in the contest".

The clashes have been playing out against a bidding war for the 59 votes of Kemi Badenoch, eliminated from the race on Tuesday and yet to openly declare in favour of any of the remaining three contenders.

Meanwhile, a YouGov survey of 725 Conservative Party members over Monday and Tuesday showed Truss would beat Sunak by 54 per cent to 35 percent, and Mordaunt would also beat him 51 percent to 37 percent.

Sunak's popularity among his parliamentary party colleagues is not reflecting equally strongly with the wider Tory membership, who will have the final say in postal ballots.

There is also some concern that Sunak's prospect to replace Boris Johnson could be hit by Conservative Campaign Headquarters' decision to send out those ballot papers early next month before the bulk of the campaign hustings have been held.