Lord Frost has ‘grave reservations’ about Penny Mordaunt as PM and says she was moved off Brexit talks

Former Brexit minister David Frost has shared his “grave reservations” about Tory leadership contest favourite Penny Mordaunt becoming prime minister in a brutal attack on her credibility.

The Brexit hardliner said the trade minister went missing during negotiations with the EU last year and became such a “problem” that he was forced to ask Boris Johnson to dismiss her from talks.

“I’m sorry to say this, I felt she did not master the detail that was necessary when we were in negotiations,” Lord Frost told TalkTV, attacking her credentials as a Brexiteer. “She wouldn’t always deliver tough messages to the EU when that was necessary.”

The right-wing Tory peer added: “She wasn’t always visible. Sometimes I didn’t even know where she was. It became such a problem that after six months I had to ask the prime minister to move her on.”

Saying he was “surprised” at her emergence as a top contender, Lord Frost said: “On the basis of what I saw I would have grave reservations about [her becoming PM].”

The former Brexit negotiator, who quit at the end of last year, even suggested that Brexit would not be safe in Ms Mordaunt’s hands if she makes it to No 10.

“If Brexit is going to be safe it’s going to need a few things,” he said. “One of them is the ability to be tough, be clear, deliver tough messages ... And I would worry, on the basis on what I’ve seen, that we wouldn’t necessarily get that from Penny.”

Leading Brexit analysist Mujtaba Rahman said Lord Frost’s view on Ms Mordaunt “is widely shared in Brussels – with one important qualification. One senior EU official tells me she ‘was even less qualified than Frost’.”

A source from Ms Mordant’s camp told The Independent: “Penny has nothing but respect for Lord Frost. He did a huge amount to assist our negotiations until he resigned from government. Penny will always fight for Brexit and always has.”

Lord Frost, admired by the hardliners in the European Research Group (ERG), suggested he would soon throw his weight behind Liz Truss, Kemi Badenoch or Suella Braverman.

“All three of those candidates … are saying very interesting things, things that the country needs to hear. I’ll says something soon on that subject,” he said on the contest.

The rival camps of Ms Truss and Ms Mordaunt engaged in a furious briefing war last night, after the outsider shook up the race by running a close second to Mr Sunak – gaining 67 to his 88.

One of Ms Truss’s allies said it was not a time for someone who needs “stabilisers”. But a shock YouGov survey showed that Ms Mordaunt would defeat Mr Sunak by 67 per cent to 28 per cent among party members – a huge margin.

Ms Truss has appealed to Brexiteers by claiming she was a “reluctant Remainer” at the 2016 Brexit referendum. “If I could vote now, I would vote to leave the European Union,” she told The Spectator.

She added: “I was a reluctant Remainer. I was loyal to the prime minister at the time, David Cameron.”

Conservative MPs in the ERG are split over which candidate will best champion the Brexit cause. ERG chair Mark Francois is backing Ms Truss, while several other leading figures in the group opt for Ms Braverman.

Theresa Villiers, one of the 28 Tory “Spartans” who voted against Theresa May’s Brexit deal three times, stunned her allies by backing Rishi Sunak in the first round.

The second round of voting by Tory MPs takes place between 11.30am and 1.30pm on Thursday, with a result announced at 3pm.