On April 16, 2025, the UK Supreme Court delivered a unanimous ruling that the words “woman” and “sex” in the Equality Act 2010 refer to biological sex. The case is likely to affect how equality law is applied across Scotland, England and Wales, especially where single-sex services and spaces are involved.
The dispute had been brought by the campaign group For Women Scotland against the Scottish government. At issue was whether a person with a gender recognition certificate should be treated as female for the purposes of the Equality Act. The court rejected that approach, saying the legislation’s reference to sex was not meant to operate as a certificated category separate from biological reality.
Judges also went out of their way to say the decision should not be read as a winner-takes-all victory. Lord Hodge, delivering the judgment, stressed that the ruling did not strip trans people of legal protection. The court said the Equality Act still protects transgender people against discrimination, including through the protected characteristic of gender reassignment as well as direct discrimination, indirect discrimination and harassment in their acquired gender.
The judgment is likely to have practical consequences for hospitals, refuges, sports clubs, prisons, hostels, changing rooms and other services that rely on single-sex rules. The court said that a certificated-sex interpretation would cut across the Act’s definitions in an incoherent way and would create problems for institutions trying to run sex-specific services consistently. It also noted that a biological-sex reading was necessary for those services to function coherently.
The political response was immediate. The Scottish government said it accepted the ruling, and First Minister John Swinney said ministers would now consider its implications. A UK government spokesperson said the decision would bring clarity for women and for service providers such as hospitals, refuges and sports clubs. Conservative leader Kemi Badenoch called it a victory for women who had felt silenced, while campaigners for trans rights said the ruling raised serious concerns about access to spaces and services.
The court’s language matters because it is likely to shape guidance, institutional policy and future litigation. The Equality and Human Rights Commission said it was updating its guidance after the judgment. What the court settled, finally, was a legal definition. What remains contested is how public bodies, employers and private operators will apply that definition in practice, especially where privacy, safety and non-discrimination obligations all meet at the same door.
