Dominic Raab has said media reports on alleged bullying are "mostly incorrect” and that he is just “setting high standards”.
The justice secretary and deputy prime minister told the BBC on Friday he would not comment on "anonymous reports in the media" adding that he “behaved professionally at all times”.
As many as 24 civil servants have now made complaints about Mr Raab’s behaviour in his current and previous roles as Brexit and international secretary. Rishi Sunak has come under pressure to explain if he knew of the investigation into his number two before appointing him last year. The prime minister has not suspended Mr Raab.
Mr Raab also gave an interview to the Daily Telegraph in which he was asked about the bullying investigation.
Asked if he was confident that he would still be in post in the summer, he repeated the line given to the BBC, saying: “I’m confident I have behaved professionally at all times.
“And I will engage with the inquiry, and of course I would not want to say anything that prejudiced it.”
He also told the newspaper that “setting high standards and zero bullying” were two aspects of managerial behaviour that were “perfectly reconcilable”.
Experienced lawyer Adam Tolley KC is currently leading an investigation, which the Esher and Walton MP has said he will respect the result of.
Dave Penman, of the FDA union which represents civil servants, criticised Mr Raab for speaking out while the investigation is ongoing and could take several weeks.
"What we need is for this inquiry to conclude as quickly as possible and for the protagonist in it, who has been reminded about confidentiality, to stop giving comments to the public,” he told the Today programme.
Labour and the Liberal Democrats have called for Mr Sunak to suspend Mr Raab while senior Tories, including former party chairman Jake Berry, have also said he should not be serving on the front benches while the probe continues.
The allegations began to emerge in November and relate to Mr Raab’s time under the governments of Theresa May and Boris Johnson as well as Mr Sunak.
Simon McDonald, former head of the diplomatic service, had said in November he warned Mr Raab and told him to change his behaviour. “It was language, it was tone, he would be very curt with people. And he did this in front of a lot of other people,” he said.
Another added: “He just doesn’t get that this behaviour is not acceptable in the modern workplace.”
Last week pro-Remain campaigner Gina Miller said the pro-Leave Mr Raab had acted in an “aggressive” manner during their encounters throughout the referendum. The lawyer said he had “bullied and demeaned” her, calling her “stupid” and “naive”.
“These are baseless and malicious claims, timed to jump on a political bandwagon and give Gina Miller the publicity she craves,” a source close to Mr Raab said.
