Dominic Raab has said he will resign from government if an inquiry upholds an allegation of bullying against him.
Eight formal complaints have been made against Mr Raab, who has served as Deputy Prime Minister and Justice Secretary since last October.
It has been alleged that the Cabinet minister has previously been “rude and aggressive” towards staff, but Mr Raab has denied the claims.
Adam Tolley KC has been investigating the allegations since being appointed by PM Rishi Sunak in November.
The complaints relate to Mr Raab’s previous periods as Justice Secretary and Foreign Secretary under Boris Johnson, and his time as Brexit Secretary under Theresa May.
Ridge On Sunday programme: “I’m not going to start speculating on what the outcome might be. Again, you’re asking me to comment on the subject matter.”
He dismissed calls to stand aside while the investigation is underway but added: “Allow me to respond in the right way at the right time, of course. Look, if an allegation of bullying is upheld, I will resign.”
Mr Raab that he has “behaved professionally throughout”, and wouldn’t comment further on the probe as he wanted to “professionally respect the integrity of that process.”
He has faced calls to step down his ministerial roles while he is investigated over the claims.
But he insisted that this was ultimately the decision of the Prime Minister, and that requiring ministers to step down whenever a complaint is made risks “politicising” the process of lodging complaints.
“I think, actually, if just by lodging complaints you can knock out a cabinet minister or a senior figure, I’m not sure that’s right,” he said.
“We believe in innocent until proven guilty in this country. And look, I’ll cooperate fully with the inquiry and I’ll respect the outcome of it.”
Ex-Tory chairman Jake Berry is among those who have suggested Mr Raab should be suspended as deputy until the inquiry is complete.
He told Radio 4’s Week in Westminster earlier this month that MPs and ministers weren’t “some form of special human being” and that they should be treated “like anyone else”.
Last month, Labour deputy leader Angela Rayner said that the number of allegations raises “more questions” about Rishi Sunak’s judgement.
“The Cabinet he appointed is awash with sleaze and scandal, but the Prime Minister is too weak to do anything about it.
“There must be no whitewash, and the Prime Minister himself must come clean on what he knew when he reappointed Dominic Raab,” she said.
On Sunday, Lib Dem Chief Whip Wendy Chamberlain called on the Prime Minister to “show some backbone” and suspend Mr Raab.
“That is what would happen to someone facing such serious allegations in any other workplace,” she said.
“The current position is completely unsustainable, how can crime victims expect justice when the minister responsible is busy trying to clear his own name?”
She added: “The longer this drags on, the more it calls into question the Prime Minister’s judgement and promise to act with integrity.”
By Chris Samuel@chrisjesamuel