John Bercow’s prospects of being elevated to the House of Lords were further undermined last night after a retired senior parliamentary official claimed he would be submitting a formal complaint detailing allegations of bullying against the controversial former Speaker.

David Leakey, a former parliamentary Black Rod, will accuse the former Commons Speaker of “intolerable rudeness and explosive behaviour” in a report to be passed to the parliamentary commissioner for standards, it was reported.

Lt Gen Leakey said he was “reluctantly” filing his own formal complaint “detailing allegations of bullying, intimidation and unacceptable behaviour” by the former Buckingham MP.

“The dossier I will submit to the commissioner will detail various incidents of bullying behaviour where I was present; the intolerable rudeness and explosive behaviour that left Bercow’s subordinates terrified was legendary, objectionable and unworthy of someone in such high public office. Many people were, frankly, terrified of Bercow – a Jekyll and Hyde character whose furious rages were belied for many by the charm and good humour he could also deploy to such effect.

“It will also spell out my own personal experience of his volatile rages, foul language and personal insults.”

Leakey, writing in the Sunday Times, said while Bercow had many strengths, including his promotion of backbench MPs, his bullying made him unsuitable for the Lords.

“If John Bercow is allowed to become a peer, the declining reputation of politicians and of parliament would, sadly, be yet further diminished,” he writes.

The Labour leader Jeremy Corbyn has nominated Bercow for a peerage after he became the first Speaker in more than two centuries to step down and not be nominated for the Lords by the government. His handling of issues around Brexit and other parliamentary business allegedly made him a target for many pro-Brexit figures who are now in power.

Leakey urges other Commons officials, including Sir David Natzler, the recently retired clerk of the House, and John Benger, Natzler’s successor, to offer evidence. He adds that Sir Lindsay Hoyle, Bercow’s successor, should withdraw his support for Bercow’s ennoblement.

He insisted he was coming forward in “the hope that others will be encouraged to come forward to file their own complaints, safe in the knowledge the new independent complaints procedure will enable their concerns to be heard”.

The latest allegations follows a complaint by Lord Lisvane, clerk of the House. Leakey insists he was not personally intimidated, having experienced “tirades from many a sergeant-major in my early days in the army”, but he added: “The visible effect of such behaviour on other parliamentary staff was appalling.”

The ex-Speaker dismissed the first complaint by Lisvane saying: “I have seen in the media that Lord Lisvane is formally complaining that I bullied staff. For the record, I categorically deny that I have ever bullied anyone, anywhere at any time.”

He went on to say the complaints had come at a “curious” time as he seeks to become a peer, and attacked the government for not elevating him to the Lords after his retirement as Speaker. “Indeed, it has been suggested to me that the government actively seeks to block any other attempt to nominate me for membership of the upper House,” he said.

Bercow left the Speaker’s chair on 31 October.

Bercow was contacted for comment last night.