The behaviour of Peter Bone left him a “broken shell”, the alleged complainant at the centre of the case has said, as the former minister faces a vote by MPs on whether he should be suspended from the Commons.

It comes after Parliament’s Independent Expert Panel (IEP) said the Wellingborough MP “committed many varied acts of bullying and one act of sexual misconduct” against a member of his staff in 2012 and 2013.

The recommended six-week suspension, if approved by MPs, could lead to Mr Bone – who has had the Tory whip removed – facing a recall petition that would pave the way for another possible by-election.

Speaking to BBC News, the alleged complainant – who remains anonymous – spoke about the alleged “physical, emotional, psychological abuse” he had endured.

The former aide also criticised the handling of his complaint by the Conservatives, claiming he was “effectively ghosted” by the party.

Mr Bone has said the allegations are “false and untrue” and “without foundation” and has vowed to continue representing his constituents.

The alleged complainant said that the experience had seen him being diagnosed with post-traumatic stress disorder.

“It unfortunately became this horrid, brutal, dark experience that left me a broken shell of the young man I once was,” the alleged complainant said.

“Peter’s behaviour was erratic. His temper was often explosive. I described it as like a, like a pendulum. He would go from one type of, kind of, personality to another. It was very hard to predict. And that kind of… left me feeling quite under siege… a kind of siege mentality in terms of the relentless shouting, the screaming, the hitting.

“The physical, emotional, psychological abuse as well as what happened later was just constantly on my mind.

“It was relentless to be honest.”

He also claimed he was “never given a clear timeline of events or even an estimated one” regarding his complaint to the Conservatives.

“I was left in this kind of limbo.

“I was effectively ghosted for three years by the party.”

A Conservative spokesperson said: “This case was investigated by CCHQ under the Party’s previous Code of Conduct and complaints process. However, the complainant withdrew from the process before the case was heard.

“Under the current process, the complainant’s case would have been referred to the ICGS as it is a workplace matter, not a Party matter.”

Five allegations about Mr Bone were made by the Westminster staffer in October 2021, with a complaint to then-prime minister Theresa May in 2017 going unresolved, according to the IEP report.

The complaints included four allegations of bullying, saying Mr Bone:

– “Verbally belittled, ridiculed, abused and humiliated” his employee;

– “Repeatedly physically struck and threw things” at him, including hitting him with his hand or an object such as a pencil or rolled-up document;

– Imposed an “unwanted and humiliating ritual” on him by forcing him to sit with his hands in his lap when the MP was unhappy with his work; and

– Ostracised the complainant following an incident on a work trip to Madrid.

In his response to the IEP’s findings, Mr Bone said: “As I have maintained throughout these proceedings, none of the misconduct allegations against me ever took place.

“They are false and untrue claims. They are without foundation.”

He said the complainant had not raised the issues during their employment and said ICGS rules meant he could not “detail my views on the huge inconsistencies and lack of evidence in the allegations”.

Mr Bone said he is “discussing with lawyers what action could and should be taken”.

Any by-election would see Rishi Sunak’s Conservatives battling to keep the Wellingborough seat Mr Bone has held since 2005.