The Green party is veering away from its founding culture towards a more leftwing authoritarianism, its former health spokesperson has claimed.

Dr Pallavi Devulapalli said trans rights had become an obvious totem in the new climate, and accused the party of trying to purge anyone with gender-critical views.

Devulapalli, a GP and member of King’s Lynn and West Norfolk council, was expelled from the party for a rules breach that she has said was due to her beliefs on gender. Her expulsion this month, she said, has exposed a rift in the party’s leadership on transgender issues that threatens to widen during this summer’s leadership election.

The party’s current co-leader Adrian Ramsay, who has argued that members should not be thrown out for saying trans women are not women, is pressing internally for Devulapalli’s expulsion to be reviewed.

A Green party spokesperson said: “We don’t comment on individual cases.”

Devulapalli was suspended last September, three months after she failed to back the party’s manifesto policy on the right of self-identification for trans people during a hustings event. Last week she was informed she had been expelled from the party after attending what Devulapalli said she thought was a social gathering, but which a disciplinary panel deemed was an official party event from which she was banned because of her suspension.

Devulapalli said the move was a “pretext” to get rid of her. She said: “They don’t like my stance on trans self ID and the trans women policy. They didn’t come out and say that so they expelled me on a technicality.”

She added: “It feels like a purge. We’ve seen the Greens veer away from its original founding culture towards a much more leftwing authoritarian culture. If you say or think the wrong thing then you’re out – that’s really worrying.”

Devulapalli is now one of 25 “Greens in Exile” – former party members who have been suspended or expelled largely for their gender critical views. Last year a court found the party had removed Dr Shahrar Ali as a party spokesperson in a procedurally unfair way that discriminated against him because of his gender critical belief. In 2021, Ali’s position as spokesperson is understood to have prompted Siân Berry, now an MP, to quit as co-leader.

Devulapalli said the party’s belief that trans women are women was “peddling a falsehood”, adding: “It denies science and denies reality and alienates the Greens from the vast majority of voters who know the truth when they see it.”

Following April’s supreme court ruling that a “woman” in the Equality Act refers only to a biological woman, the Greens’ policy has come under strain. In interviews since, Ramsay, who is standing again as co-leader with fellow MP Ellie Chowns, has refused to commit to an answer, but Carla Denyer, who is standing down as co-leader, has said that “trans women are women [and] trans men are men”. Zack Polanski, a leadership challenger, is campaigning on the slogan “trans rights are human rights”.

Devulapalli fears that if Polanski wins, the party will become more “authoritarian” and less tolerant of gender critical views as it tries to appeal to disillusioned Labour supporters. She said: “A lot of members have said they will leave the party if he’s elected. People are trying to reclaim the Greens back to being a party of democratic values and science.”

Since her expulsion Devulapalli says she has had dozens of messages of support, including from fellow GPs and prominent Greens such as the party’s former candidate for London mayor Jenny Jones and another former Green party health spokesperson, Larry Sanders, who called for “debate not expulsion”.

Devulapalli said accusations of transphobia, which she denies, had contributed to a culture of fear within the party. “People are afraid of being bullied online and being cast out of the party. But speaking up calmly, rationally and with compassion is important.”