Tory former Cabinet minister Sir Alok Sharma has denied allegations that he “bullied” civil servants.

Sir Alok, who was president of the Cop26 climate summit, said he had never been made aware of any complaints against him.

He was alleged to have been difficult to work with, insulting staff’s work and using expletives, Bloomberg reported, citing four senior officials.

He was also said to have bullied junior civil servants by calling them out of the blue to disparage their work during the pandemic, with the allegations spanning his time as business secretary and his climate change presidency between 2020 and 2022.

It was reported that concerns about Sir Alok’s behaviour were raised with Civil Service bosses at least four times in 2020, though they were not official complaints.

It comes as Rishi Sunak’s deputy Dominic Raab is under investigation over eight formal complaints about his behaviour.

The Prime Minister, who pledged to uphold “integrity, professionalism and accountability” in government, is bracing for the probe led by senior lawyer Adam Tolley KC into Mr Raab’s conduct during stints in three departments to conclude.

Mr Raab, who is also Justice Secretary, has insisted he is not a bully.

In response to the allegations against Sir Alok, a Government spokesperson said: “We have no records of any complaints.”

Sir Alok, now a Tory backbencher, said: “I have never been made aware of any ‘informal complaints’ or otherwise from staff. The Cabinet Office has confirmed that there are no records of any informal or formal complaints across government about me. I refute strongly these allegations.

“I have worked with hundreds of officials as a government minister and always felt I maintained a good relationship with them, exemplified by seven of my BEIS Private Office team, those officials working most closely with me, choosing to join my Cop Private Office alongside those I had worked with in previous ministerial roles.”

The PA news agency understands that the calls made by Sir Alok to staff were during work hours, with the allegation regarded as weak among some in Whitehall where he is said to enjoy a good reputation.

Sir Alok lost his seat around the Cabinet table in Mr Sunak’s reshuffle upon entering No 10 in October.

The Reading West MP is expected to be on Boris Johnson’s resignation honours list.