University of Bradford alumnus Sir Gavin Williamson is facing an investigation amid fresh bullying claims

Cabinet Office minister Sir Gavin allegedly told a senior civil servant to “slit your throat” in what they claimed was a bullying campaign.

The Ministry of Defence (MoD) official told the Guardian that the-then defence secretary made the remarks in front of colleagues in a meeting.

The official also reported another occasion when he allegedly told them to “jump out of the window”.

Sir Gavin said he “strongly” rejects the allegation and insisted he has “enjoyed good working relationships” with officials.

The newspaper said the official, who later left government, complained to the MoD’s head of human resources about the alleged incidents.

But it was understood the Cabinet Office’s propriety and ethics team has not received a complaint about Sir Gavin’s conduct towards officials.

A Cabinet Office spokesman said: “The Cabinet Office has not received notice of any formal complaints about Gavin Williamson’s behaviour from his time at the Ministry of Defence or any other department.”

But the allegations, including that Sir Gavin “deliberately demeaned and intimidated” the civil servant on a regular basis, is bound to add to the calls for his sacking.

Rishi Sunak is under increasing pressure over his decision to bring his ally back into Government.

The Prime Minister has retained total confidence in Sir Gavin, Downing Street said.

Mr Sunak made the appointment when he knew he was under investigation for allegedly bullying former chief whip Wendy Morton.

In a series of expletive-laden texts exposed over the weekend, Sir Gavin accused Ms Morton of seeking to “punish” MPs out of favour with then-premier Liz Truss.

He appeared to accuse Ms Morton of excluding some MPs from the Queen’s funeral, warning: “There is a price for everything.”

Sir Gavin issued a statement denying the broad allegations in The Guardian’s report but did not specifically deny using the language alleged.

“I strongly reject this allegation and have enjoyed good working relationships with the many brilliant officials I have worked with across government,” he said.

“No specific allegations have ever been brought to my attention.”

Sir Gavin graduated from the University of Bradford with a BSc in Social Sciences in 1997.

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