What is a woman? The battle of Hampstead Heath

The Supreme Court has spoken but not everyone is happy with the judgment.

This piece was originally published in French on 22 July 2025.

Back in April, the UK Supreme Court ruled unanimously that a woman is quite clearly defined by her biological sex. However, the judgment is meeting resistance from some service providers who think differently.

The latest controversy involves the open-air swimming facilities on Hampstead Heath in North London. The three swimming ponds were originally dug as reservoirs, but people have been bathing in them for generations. Separate men’s and women’s ponds cater for each sex, while the mixed pond welcomes everybody. Surely, an example of good practice that is inclusive of all?

The problem, once again, is who counts as a woman. The association that runs the women’s pond has stated, “trans women have been swimming there for many years without incident.” Last year, members of the association voted to reject a resolution that would have limited use of the pond to “those born female in sex.” Instead, it has been reported that new signage will declare that trans women can use the pond, changing rooms, and showers.

It looks increasingly likely that the matter will end up back in court. The campaign group Sex Matters has launched a £50,000 appeal to fund legal action against the City of London Corporation, which owns the ponds. Within a week, they were well over halfway to their target. Thus far, the corporation is unrepentant, arguing that for now at least, its policy of allowing anyone who identifies as a woman to use the women’s pond will “remain in place.”

But if most of the members who use the women’s pond are happy with the status quo – that resolution was apparently “resoundingly defeated” – should they not be allowed to continue to welcome trans women while excluding men? Sex Matters argues that this would be unlawful because the Supreme Court ruled that trans women are men for the purposes of equality legislation and therefore must also be excluded from women’s single-sex services.

Previous Protests and Legal Loopholes

This is not the first time the Hampstead Heath ponds have made a splash in the media. Back in 2018, a group of women decided to self-identify as men for the day and gatecrash the men’s pond. Dressed in fake beards, the women jumped into the water to protest plans to change the law to allow anyone to change their legal gender without medical checks. Police were called, and the women were promptly escorted from the pond.

It was a rather good-natured protest. One of the police officers posed for photographs with the women, and it was smiles all round. But the protestors attracted public attention at a time when self-identification was being introduced quietly in other countries. Ultimately, the law in the United Kingdom was not changed. The British can change the sex marker on their birth certificates, but only after providing medical reports that include a diagnosis of gender dysphoria.

Since the Supreme Court judgment, even an edited birth certificate does not allow access to spaces and services that are provided for the other sex. Unfortunately for service providers who do want to apply the law, it is impossible to distinguish between a woman’s birth certificate and one produced by a trans woman who has gone through the full legal process. The two documents follow exactly the same format.

Earlier this summer, it was reported that a train driver claimed they were not transgender but “just ugly” when challenged by colleagues. The train drivers’ union suggested that was just one example of its members being questioned about their sex. But while questions can be asked, there is no way to tell that the answers are truthful. There is no mechanism to check whether the sex marked on their birth certificate has been changed.

The Return to Common Sense

It’s a wonder how human society managed for so long without suddenly running into the buffers. But perhaps the truth is that we can all tell the difference between men and women. That instinct will not be fooled by legal paperwork brandished by a trans woman who clearly looks more like a man than a supposedly ugly woman. We just know. Until recently, that was all that mattered. Previous generations were able to distinguish men from women with neither paperwork nor knowledge of chromosomes, and they did not have the problems that we face today. They were simpler times, but that common-sense approach worked.

The big mistake of the last 15 years has been to try to shift the decision-making process from the group to the individual. Previously, when someone announced themselves to be the opposite sex, they would not get far if their declaration contradicted the evidence of everyone else’s eyes. More recent policy might demand that nothing is said, but it cannot compel anyone’s thoughts, let alone their feelings. The resulting mess is unsatisfactory for everyone.

An employment tribunal in Scotland is currently* hearing a case brought by nurse Sandie Peggie against her employer, NHS Fife. Peggie objected to the presence of Beth Upton, a transgender doctor, in a women’s changing room. The law in the UK is now clear: Upton is male, so should not have been there.

However, that’s not the outcome that the employer’s diversity officer thinks ought to exist. She claimed that there was a “pretty wide consensus” that transgender staff should be able to use the facilities that aligned with their self-identified gender. As for biological sex, she suggested that it was “far more complex” than whether someone had a male or female body. She went on to tell the tribunal that she couldn’t be sure of her own sex.

Whether she believes that nonsense, of course, is up to her, but the truth is simple. We don’t need any knowledge of biology to distinguish men from women. We should be allowed to get on and do it. NHS Fife would not have wasted public money defending Peggie’s claims, while the swimmers in the Hampstead women’s pond would not need to become embroiled in a legal challenge to keep out people they know to be men.

As for the sex of the ugly train driver, their colleagues will not need to see a birth certificate to decide. It is common sense – a perception shared by everyone. We all know this, and the sooner we get back to it, the better it will be for everyone, diversity officers included.

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By Debbie Hayton

Debbie Hayton is a teacher and journalist.

Her book, Transsexual Apostate – My Journey Back to Reality is published by Forum

* This article was first published in French by Le Point on 22 July 2025: Femme ou pas femme ? La bataille judiciaire des étangs de Londres.