The transgender issue is the most sensitive in Britain today, sparking passionate debate among equal-rights campaigners.

But now that passion has erupted into the sort of outright violence normally associated with football hooligans.

Two factions – the Trans-Exclusionary Radical Feminists (or so-called TERFs) and their bitter enemies Trans Activists – clashed in an unseemly bust-up that ended with a 60-year-old woman being bundled to the ground and punched in the face. The incident was caught on video and is now being investigated by the police.

Mother-of-two Maria MacLachlan, who describes herself as a ‘gender critical feminist’, was attacked at Speakers’ Corner in London’s Hyde Park at about 7pm on Wednesday.

Gender warfare: A hoodie-wearing protester raises a fist during the brawl

She had joined around 50 fellow TERFs who were to be given details of the secret location for a talk entitled What Is Gender? The Gender Recognition Act And Beyond.

TERFs are feminists who are opposed to some campaigning by transgender women.

The event was originally scheduled to be held at a community centre in New Cross, South-East London, but was switched following online warnings of a protest from Trans Activists.

Among the groups threatening to protest were the LGBTQ+ Society from Goldsmiths University, an organisation called Sisters Uncut, and Action For Trans Health London. Ms MacLachlan told The Mail on Sunday: ‘I was chatting to one of the speakers, Miranda Yardley, and people started to come who looked different to the rest of us. There was quite a generation thing.

‘These studenty-looking types were turning up and some arguments started to take place but I kept well out of it.’

Ms Yardley is a prominent transgender writer and was guest speaker at the event along with Dr Julia Long, who describes herself as a ‘lesbian feminist and defender of women-only spaces’. Ms MacLachlan said: ‘Julia said she was going to sing a song she had written. She took a megaphone and as soon as she put it to her lips, these kids started shouting, “When the TERFs attack, we fight back.”

‘I thought, “I can film this, it will be interesting.” They were getting louder and louder. Then suddenly someone tried to grab my camera. It was scary. Someone kept trying to get my camera. I think it was a girl, but I couldn’t tell because they had a hoodie over their eyes.’

Flashpoint: The activist holds Maria MacLachlan, who was left shaken

Mother-of-two Maria MacLachlan (pictured), who describes herself as a ‘gender critical feminist’, was attacked at Speakers’ Corner in London’s Hyde Park at about 7pm on Wednesday

Footage of the incident was uploaded to YouTube the day after the alleged attack, and it has since been viewed tens of thousands of times.

In a statement to police, Ms MacLachlan later identified a trans-woman who is currently trying to raise £5,000 for vocal-cord surgery to make her voice higher, as one of her attackers.

Her Lumix camera was smashed and the memory card stolen. She also sustained a nasty bruise on her face, red marks on her neck and grazed knees. She added: ‘I didn’t go to hospital but it has really shaken me up.’

Several feminists called 999 and three cars containing six officers arrived on the scene, but no arrests were made.

Notes were passed among the feminists letting them know the secret venue was the University Women’s Club in Mayfair.

They left in small groups hoping not to be followed but were tracked down by the activists. Another feminist, Jen Izaakson, said tension remained high at the venue. She added: ‘The staff had to form a human chain to let our people in and keep protesters out.’

Because students from Goldsmiths had been so vocal in opposing the original meeting, the feminists believe they formed a section of the protesters.

A spokesman for the university said: ‘Goldsmiths prides itself on its diverse and inclusive community. We uphold the right to peaceful protest but cannot condone violence.’

Action for Trans Health London issued a statement saying: ‘We condemn violence against women in all forms. We’re proud that many self-organising activists, allies and supporters stood against hatred, misogyny and intimidation.’

A Scotland Yard spokesman confirmed an investigation was ongoing and video evidence would form part of their inquiries.