Tory leadership race: first of three TV debates on Friday

Mordaunt, Truss, Sunak, Badenoch and Tugendhat face 90-minute grilling from voters

Clockwise from top left: Rishi Sunak, Kemi Badenoch, Penny Mordaunt, Boris Johnson, Tom Tugendhat, and Liz Truss. PA / Reuters / UK Parliament

The five remaining candidates in the race to lead Britain's Conservative Party will face their toughest grilling yet on Friday, in the first of three TV debates that could make or break their chances of becoming prime minister.

After days of choreographed campaign speeches, the 90-minute Channel 4 debate will force the candidates to field questions from a studio audience made up of potential swing voters.

For the two relative outsiders, former equalities minister Kemi Badenoch and backbench MP Tom Tugendhat, the debates are potentially a final chance to impress after both candidates resisted pressure to drop out.

"I have never turned down a challenge because the odds were against me. I don’t plan to start now," said former soldier Mr Tugendhat.

The three front-runners, former chancellor Rishi Sunak, trade minister Penny Mordaunt and Foreign Secretary Liz Truss, are competing for two spaces in the final run-off, when the 200,000 Conservative members will decide the next leader.

How they fare in front of the public could help sway undecided Conservative Party MPs who will cut the field down to two in three more rounds of balloting next week.

When Tory MPs last chose a leader in 2019, a poor debate performance by maverick MP Rory Stewart sapped his momentum and he was knocked out of the race the next day.

Another TV turning point came at the general election in 2010, when Liberal Democrat leader Nick Clegg enjoyed a surge in the polls as the debates gave voters a closer look at the third party.

"This debate will be essential viewing for those wanting to know more about our next prime minister and what she or he stands for," said Channel 4 executive Louisa Compton of Friday's showdown.

ITV will host a second televised debate on Sunday. Sky News plans to broadcast a third on Tuesday, by which time the field will have narrowed further.

The debate comes amid increasingly vicious briefings between the rival camps despite the candidates insisting they want to keep things civil.

Knives were out for Ms Mordaunt on the Tory right after she caught many by surprise by leading Ms Truss in the first two rounds of voting.

It raised the prospect of a Mordaunt-Sunak contest that would be likely to disappoint right-wing MPs who see their views as too moderate.

Former Brexit negotiator Lord Frost, who weighed in with an outspken attack on Ms Mordaunt, said on Friday that Ms Badenoch should pull out and get behind Ms Truss in a so-called "unite the right" ticket.

"I urge Kemi to stand down in return for a serious job in a Truss administration," wrote Lord Frost in an article for the Daily Telegraph.

But the Badenoch camp said a fresh start was needed after the tumultuous Boris Johnson years and that their candidate should not be judged for a lack of ministerial experience.

"She has had two years’ more experience than both David Cameron and Tony Blair, who both went and did very well in elections," Tory MP Justin Tomlinson told Times Radio.

Conservatives on the campaign trail - in pictures

And a Mordaunt supporter, Dame Maria Miller, said Lord Frost was wrong about the candidate and described her as "one of the leading proponents of Brexit".

Another Truss supporter, former party leader Iain Duncan Smith, took aim at Ms Mordaunt's out-of-the-blue popularity by saying the Tories "can’t just elect somebody because for a short period of time they may look better than others".

"What we’re actually electing is not, in a way, a popularity contest. We’re electing somebody who has to govern for probably two years with a huge set of crises," he told LBC radio.

Ms Truss received a boost late on Thursday when Suella Braverman, the attorney general, backed the foreign secretary's campaign after being eliminated in the second round of voting.

Hoovering up the bloc of 27 Braverman votes could offer Ms Truss a way back into contention after her 64 votes in round two put her some way behind Ms Mordaunt on 83.

Mr Sunak was in the lead on 101. Ms Badenoch had 49 and Mr Tugendhat 32. Anyone who gets 120 will effectively be guaranteed a place in the final two.