Boris Johnson has apologised for making Chris Pincher deputy chief whip.
The prime minister said “in hindsight it was the wrong thing to do”.
Johnson made his comments in a hastily-arranged TV interview amid mounting pressure over his leadership.
But within minutes, both Sajid Javid and Rishi Sunak dramatically resigned from the cabinet.
The PM’s comments came after it emerged he was told in 2019 that a sexual harassment complaint against Pincher when he was a Foreign Office minister was upheld.
Downing Street had repeatedly insisted that the PM was not aware of any “specific allegations” against the Tamworth MP prior to putting him in the whips’ office in February.
Pincher resigned from the post on Thursday after he was accused of drunkenly groping two men at a private members’ club in London last week.
The PM said Pincher should have been sacked from the government after the 2019 incident.
Asked if it was an error to appoint Pincher, the PM said: “I think it was a mistake and I apologise for it. In hindsight it was the wrong thing to do.
“I apologise to everybody who has been badly affected by it. I want to make absolutely clear that there’s no place in this government for anybody who is predatory or who abuses their position of power.”
Speaking to reporters in his Commons office, he did not deny joking: “Pincher by name, Pincher by nature”.
Asked if he had made the comment, he said: “What I can tell you is that, if I look at the background of this and why I regret it so much, is that about three years ago there was a complaint made against Chris Pincher in the Foreign Office, the complaint was cleared up, he apologised.
“It was raised with me, orally, I was briefed on what had happened. If I had my time again I would think back on it and recognise that he wasn’t going to learn a lesson and he wasn’t going to change and I regret that.”