David Frost has ‘grave reservations’ about Penny Mordaunt as Tory leader

The Conservative leadership candidate Penny Mordaunt has come under fire from supporters of her rival Liz Truss who expressed “grave reservations” about her, as tensions ratchet up in the race for the second place on the final leadership ballot paper.

After Mordaunt usurped Truss to trail Rishi Sunak in Wednesday’s first ballot of Tory MPs, allies of the foreign secretary sought to sow doubt about the trade minister’s record on Brexit.

David Frost, who led the UK’s negotiations with the EU, said when Mordaunt was his deputy she “wasn’t fully accountable or always visible” during talks with Brussels.

“To be honest, I’m quite surprised she is where she is in this race,” he told TalkTV on Thursday. “She was my deputy – notionally more than really – in the Brexit talks last year.

“I’m sorry to say this, she did not master the necessary detail in the negotiations last year. She wouldn’t always deliver tough messages to the EU when that was necessary and I’m afraid she wasn’t fully accountable or always visible. Sometimes I didn’t even know where she was.

“I’m afraid this became such a problem that after six months I had to ask the PM to move her on and find somebody else to support me. From the basis of what I saw, I would have grave reservations.”

Simon Clarke, the chief secretary to the Treasury and also a Truss supporter, said Frost’s warning was “a really serious one”. “Conservatives – and far more importantly our country – need a leader who is tested and ready,” he added.

Another anonymous Truss backer said overnight it was the wrong moment to install a prime minister who needed “stabilisers”.

British public ‘fed up’ of broken promises, says Penny Mordaunt – video

Mordaunt, who backed Brexit before the referendum in 2016, has sought to rely on those credentials as part of the contest, telling supporters at her campaign launch on Wednesday that she wanted to fully unleash the potentials of a “Brexit dividend”.

Truss is a Brexit convert who was part of George Osborne’s Treasury team during the remain campaign that was accused of peddling “project fear”.

Truss’s supporters were rattled on Wednesday night by Mordaunt pipping her to second place by taking 67 votes, while the foreign secretary got 50. Sunak was the frontrunner with 88.

Mordaunt, who had little interaction with the EU during her ministerial career, is not well known in Brussels. Those who have followed her career are not enthused about her moving to No 10. “We are bracing [ourselves],” said one EU official. “Not because she’d be a tough interlocutor. Because her reputation is she is totally incompetent. And that won’t help.”

The former defence minister gained prominence in the 2016 EU referendum campaign when she made repeated false claims that the UK could not veto Turkey’s EU membership. She told LBC this week that she stood by those comments.

European diplomats are more familiar with other contenders, such as Truss, who has led the push to unilaterally rewrite the Northern Ireland protocol, a step that has brought EU-UK relations to a new low.

Some think the current frontrunner, Rishi Sunak, might take a more pragmatic approach to the protocol, because of the potential damage a trade war with the EU would inflict on the already weak UK economy. But few see any prospect of an improvement in EU-UK relations.

“We have a hope that it might improve one day, but we don’t see in any of the candidates a radical change,” a senior EU diplomat said. “Even if the style is different, the substance will not be very different.”

Meanwhile a battle is under way among the remaining candidates’ camps to hoover up supporters of those who dropped out: Jeremy Hunt has endorsed Sunak but Nadhim Zahawi has remained silent.

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Truss kicked off her leadership campaign with a rally on Thursday morning, as allies called on contenders Suella Braverman and Kemi Badenoch to unite behind her.

In an attempt to reinvigorate her campaign to be the next prime minister, Truss was expected to say her mission remained making the UK “an aspiration nation, where every child, every person has the best opportunity to succeed”.

Truss has also reiterated her promise to cut taxes, including by reversing the recent national insurance increase, which is earmarked to pay for social care. In an interview with the Spectator she suggested tax cuts could be paid for through extra borrowing.