Dominic Raab ‘was warned by Boris Johnson about his conduct’

Boris Johnson privately warned Dominic Raab about his conduct and has given evidence to the bullying investigation into his former Cabinet colleague, it has been reported.

The independent lawyer looking into formal complaints against Mr Raab about his treatment of staff has interviewed the former prime minister about his former deputy in No 10, according to The Telegraph.

The deputy prime minister and justice secretary vehemently denies the bullying allegations against him, saying he was just “setting high standards” and that he “behaved professionally at all times”.

But he said last month he would resign from government if the claims are upheld by the investigation, conceding he could not carry on.

It is highly unusual for a former prime minister to be involved in an investigation launched by Downing Street, but lawyer Adam Tolley KC, whom Rishi Sunak asked to investigate the claims, has interviewed Mr Johnson, according toThe Telegraph.

How long Mr Johnson’s interview was and what was discussed are not known, but he is one of dozens of people who have given evidence.

The newspaper also said the former prime minister privately warned Mr Raab about his conduct.

The FDA union, which represents civil servants, says it understands the complaints against Mr Raab span several years. One ex-colleague has claimed he reduced them to tears.

Mr Raab, who was also foreign secretary under Mr Johnson for a time, stood in for the prime minister in the Commons and at Covid briefings while the then prime minister was ill with Covid.

After Liz Truss quit No 10 in the autumn, the ex-prime minister was on the verge of running again as Conservative leader against Mr Sunak, but in the end pulled out.

Asked on Sky News about calls for his resignation, Mr Raab earlier said: “Just by lodging complaints you can knock out a cabinet minister – I’m not sure that’s right. We believe innocent until proven guilty in this country.”

But he also said he had learnt lessons from his dealings with civil servants in the past.

Allies have suggested that civil servants are trying to push him out, with one former colleague saying “there is a clear attempt by a group of politically motivated mandarins to get him”.

A spokesman for Mr Raab said they would not comment while the investigation was continuing, adding: “We don’t want to prejudice it in any way so I can’t comment.”

Mr Johnson’s spokesman said: “It would be inappropriate to comment on an ongoing inquiry.”

The investigation is understood to be in its final stages. Rishi Sunak has said he will wait to see the outcome before making any decision on Mr Raab’s future in the Cabinet.

A Cabinet Office spokesman said: “Adam Tolley KC is conducting an independent investigation into allegations against Dominic Raab. It would not be appropriate to comment further whilst that is ongoing.”