The Equality and Human Rights Commission published an updated code of practice on Thursday afternoon saying single-sex spaces such as toilets and changing rooms must be used on the basis of biological sex, and that transgender people may not access spaces that match their lived gender.

Stephen Whittle, 70, was visiting the Chelsea flower show with his wife when the guidance landed. The veteran campaigner, who led the push for gender recognition across the UK in the 1990s, said he had spent decades using male facilities and could not imagine using the ladies, adding that he was trying to calm people down and tell them they would get through the change.

The 340-page code is the clearest practical fallout yet from the supreme court ruling on biological sex in April 2025, ending months of uncertainty over how services should apply the law. For groups that run women-centred services, the document brings a legal line into sharper focus, but it also forces them to decide how quickly they can rewrite policies, websites and forms to match it.

Katie Russell, chief executive and co-founder of Support After Rape and Sexual Violence Leeds, said her service had been taking bespoke legal advice and consulting with users since April last year. By Friday morning, she said, the organisation was still working through the code and changing its governing documents and language. Russell said the charity was gradually making clear that it remained women-centred while including trans women, and that it wanted to operate within the law while continuing to model its intersectional feminist values. She described the approach as super-clear and said the organisation had already decided it had lost the right to call itself women-only.

That issue matters in practical terms because Support After Rape and Sexual Violence Leeds supported 1,700 individuals last year, and trans women and non-binary clients made up only a tiny percentage of that total. Russell said the charity believed the change remained a proportionate means of achieving a legitimate aim, asking where else those clients would go. The service is now reviewing a 340-page code while reshaping the language it uses to describe itself.

There is still friction beneath the clarity of the new rules. Russell said services like hers had spent more than a year preparing for this moment, but many businesses contacted about the update said they wanted more time to study the detail. The guidance also leaves front-line staff carrying the burden of application, turning everyday spaces into places where workers may have to decide who belongs and who does not.

The sharpest criticism came from Lush, which said the guidance was a significant setback for human rights in the UK. Andrew Butler, the brand’s campaign lead, said it puts frontline service providers, retail workers and many others in the position of policing people’s gender based on perception, with their organisations’ policies now having to absorb that pressure. Gender-critical groups, by contrast, welcomed the update as a consolidation of the court’s victory and a long-awaited answer to the limbo that followed the April ruling.

For Whittle, who spent the 1990s fighting for recognition and is now watching the rules settle in the opposite direction, the day carried its own kind of history. The question is no longer whether guidance will come, but how fast institutions can make it real, and how many people will feel the shift first.