The University of Cambridge’s prestigious Institute of Astronomy has been accused of tolerating misogyny and a “cycle of bullying” in an employment tribunal.

The claim, brought by a professor of astrophysics, Wyn Evans, also alleges the University of Cambridge has retaliated against whistleblowers.

The Institute of Astronomy is one of the largest departments of its kind, where researchers grapple with questions about the formation of the solar system and the evolution of the universe.

Evans, who last year stood to be the University of Cambridge’s chancellor with an anti-bullying manifesto, said that the Institute of Astronomy suffers from “a bad history of misogyny”. Evans claimed that one woman in the department was “hounded out of a job”, another had been “left a frightened woman” and a third had faced “aggressive professors” at the institute.

The university denies Evans’ claims and accuses him of a vendetta against the institute’s director, a claim in turn denied by Evans.

With his voice breaking in the second week of a tribunal in Bury St Edmunds, Evans said he had become concerned about the welfare of a colleague, Dr Gudrun Tausch-Pebody, in 2021, adding: “We were faced with a critical situation.”

Akua Reindorf KC, for the University of Cambridge, suggested Evans’ emotional testimony in court about the suicide of a former colleague amounted to “crocodile tears”. “No, and that is an offensive thing to say,” Evans replied.

Dr Tausch-Pebody joined the institute in 2012 as a European Commission contracts manager. In June 2021, she was issued with an “end of contract” notice despite, Evans alleges, funding being available to support her role. Evans claimed Dr Tausch-Pebody was being deliberately undermined by a senior colleague, an allegation the university denies.

In a written submission, Dr Tausch-Pebody expressed her gratitude to Evans for his “courage” in intervening to protect her from alleged bullying by a senior member of staff. “Prof Evans’ concern for me was based on my distress. He saw a pattern of repeated and seemingly tolerated mistreatment of female members of the administrative staff,” she wrote. “What was done with this end-of-contract letter was akin to psychological torture.”

Dr Tausch-Pebody claimed that her work was undermined, discredited and diminished by a superior which had an “indelible effect” on her mental health.

Evans described one evening “agonising over what to do, whom to contact, and whether Dr Tausch-Pebody would still be alive the next day. When I checked my email the next morning, I felt a wave of relief to see messages from her sent overnight. She might not have slept, but at least she was still alive.”

Evans submitted what he alleges were whistleblowing disclosures setting out his concerns about the treatment of Dr Tausch-Pebody by senior staff at the institute. Dr Evans also claimed the institute had a “terrible record” of supporting female administrative staff.

He claimed no action was taken to protect Dr Tausch-Pebody, but grievances were instead raised against himself and two other professors by the Institute of Astronomy’s director, Prof Richard McMahon. Evans said: “It is unprecedented in Cambridge University for a head of department to make a grievance against three professors simultaneously.”

The university dismissed McMahon’s allegations against the professors, saying no evidence had been submitted in support of the claims. Evans told the tribunal that despite the lack of evidence, the complaint “took almost two years for the university to dismiss”.

His colleague, Prof Vasily Belokurov, who this month was jointly awarded the highly prestigious 2026 Kavli prize for astrophysics, said in a written submission: “The outcome of the extended investigations into Wyn Evans … was that our research group faced near collapse.”

Evans initiated separate legal proceedings against McMahon, claiming allegations made in the grievance were defamatory. He has told the tribunal the head of department fought the libel proceedings “relying on the university’s support and funding through its insurance policy”. In 2023, a preliminary issues judgment concluded the statements made by McMahon were defamatory. The case has since been settled out of court.

Evans claims that since making a complaint in 2021, he has “lost all faith in the basic integrity of senior people in my university … Looking back, I could never have imagined the scale of destruction in my life that would follow.”

The tribunal is being heard to assess whether Evans received detrimental treatment as a result of whistleblowing.

Reindorf claimed Evans’ allegations were part of an “obsessive vendetta” against McMahon. She said the University of Cambridge is defending Evans’ claim “at very great expense”.

McMahon denies the allegations. He is scheduled to give evidence in person this week. A spokesperson for the University of Cambridge said: “The university strongly rejects these claims and is vigorously defending this case.”

The tribunal continues.