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

Opposition Labour Party leader Keir Starmer called Williamson a “pathetic bully” and challenged Sunak over his decision to appoint him.

Sunak, who took office late October as Britain’s third prime minister in two months, has also faced criticism for reappointing Suella Braverman as interior minister just days after she was fired by his predecessor for security breaches.

Williamson said late yesterday he was stepping down after media reported that colleagues had accused him of bullying, with one saying he told a government official to “slit your throat.”

Williamson, who has been fired from other ministerial roles twice in the last four years, said he was complying with a complaints process and he refuted the characterisation of the messages.

Sunak said he accepted Williamson’s resignation with “great sadness.”