LONDON - British Prime Minister Rishi Sunak said on Wednesday he regretted appointing Mr Gavin Williamson as a junior minister in the Cabinet Office.

Mr Williamson was forced to resign on Tuesday over claims that he bullied his colleagues.

“I obviously regret appointing someone who has had to resign in these circumstances,” Mr Sunak said during Prime Minister’s Questions in Parliament.

“Unequivocally, the behaviour complained of was unacceptable,” he added, while stressing he did not know of “specific concerns” about Mr Williamson arising from his past government roles.

Mr Williamson resigned from Mr Sunak’s government to “comply fully” with investigators.

Mr Sunak has come under fire for the choice of some of his ministers after he was elected as Britain’s third prime minister in two months, vowing to restore integrity and professionalism to the heart of government.

He appointed Mr Williamson, who was fired as defence minister and education minister by Mr Sunak’s predecessors, to a ministerial role in the Cabinet Office just two weeks ago.

The Sunday Times and other newspapers have since reported that Mr Williamson treated government officials aggressively and sent expletive-laden messages to colleagues.

On Monday, The Guardian newspaper reported that Mr Williamson bullied a senior civil servant in the Ministry of Defence and told him to “slit your throat” while serving as defence secretary under former prime minister Theresa May.

On Tuesday, Channel 4 News aired an interview with Mr Williamson’s former deputy when he was chief Whip, Ms Anne Milton, who said his behaviour was “threatening” and “intimidating” when he held the post, and that he would use MPs’ health problems as “leverage”.

She recounted one incident when he asked her to give a cheque to an MP who needed financial assistance.

“And he waved it under my nose and said, ‘Make sure when you give him this check, he knows I now own him’,” she said. “I don’t think it was a joke. It was the seriousness with which he said it.”

Mr Williamson said in a letter to Mr Sunak on Tuesday that he was complying with a complaints process.

He added that while he refuted the characterisation of the messages, he recognised that they were becoming a distraction for the government.

“I have, therefore, decided to step back from government, so that I can comply fully with the complaints process that is underway and clear my name of any wrongdoing,” he said in the letter, which he published on Twitter.

“It is with real sadness that I tender my resignation.” BLOOMBERG, REUTERS