April 2025 — London
The UK Supreme Court has issued a landmark ruling that the term “sex” in the Equality Act 2010 refers strictly to biological sex, rather than gender identity.
The decision, delivered by Lord Hodge in a unanimous judgment, carries significant implications for how equality law applies to transgender people, particularly trans women.
According to the judgment, “‘woman’ and ‘sex’ in the Equality Act are to be understood as referring to biological women and biological sex.”
Lord Hodge added that the decision should not be seen as a victory for any group at the expense of another.
The case originated from a legal challenge brought by For Women Scotland (FWS) after the Scottish Parliament passed legislation in 2018 to achieve gender balance on public boards. FWS argued that trans women should not be included under the category of “woman” unless they were biologically female.
This view opposed the Scottish Government, which stated that trans women who hold a Gender Recognition Certificate (GRC)—a legal document affirming a person’s gender identity—should be recognised under the law.
The case centred on how the law defines the protected characteristic of sex and how it interacts with other protected identities, such as gender reassignment. While sex and gender reassignment are safeguarded under the Equality Act, the court clarified that these are distinct legal categories.
Lord Hodge explained that while trans individuals are protected from discrimination under the characteristic of gender reassignment, the definition of “sex” in the Act must be interpreted in terms of biological sex, or the sex assigned at birth.
The ruling also addressed broader implications for access to single-sex services and spaces, including public restrooms, domestic violence shelters, and sports teams. While trans women can still access these services without a GRC, they can legally be excluded if there is a legitimate aim under equality law.
The UK Government welcomed the decision, saying it offers “clarity and confidence” for service providers, including hospitals and women’s refuges. However, critics have raised alarms about the implications for transgender rights.
Scottish First Minister John Swinney said his government’s advocates expressed outrage and concern.
Sophie Molly, a trans rights activist in Scotland, criticized it as a step backwards:
“Trans rights are being stripped away under the pretense of defending women’s rights. Trans women are women. There should be no separate law for cis and trans women.”
She added, “I will continue to use female spaces. I am a woman, and it is my right.”
The Good Law Project, a governance and legal watchdog, also condemned the ruling, noting that the Supreme Court “did not hear from a single trans person” and that it “sets a dangerous precedent.”
Scottish Greens MSP Maggie Chapman called the judgment a “huge blow” to some of the most marginalized in society and warned it could erode crucial legal protections for trans people.
Meanwhile, For Women Scotland celebrated the ruling on social media, declaring, “Yaaaaaaaaaaaaaaaaaaaaaaaaaaaaas #WeKnowWhatAWomanIs.”
The ruling is expected to have a lasting impact on the interpretation of equality law and the rights of transgender people in the UK.
