The U.K. Supreme Court commenced hearings on a significant legal case on Tuesday, centering around the term “woman” in a dispute involving a women’s rights advocacy group and the Scottish government.
Five judges at the nation’s top court are examining whether individuals who are transgender and possess a gender recognition certificate—identifying them as female—can be classified as women regarding equality laws.
Although the matter primarily pertains to Scottish legislation, the advocate group For Women Scotland (FWS) argues that the outcome could influence rights associated with sex throughout the entire United Kingdom, affecting single-sex facilities such as restrooms and healthcare wards.

The roots of this legal challenge lie in a 2018 statute enacted by the Scottish Parliament, which mandated that public bodies in Scotland achieve 50% female representation on their boards.
This law explicitly included transgender women in its definition of women.
The women’s rights group contested the legitimacy of this legislative definition, asserting that it overstepped the parliamentary authority.
Consequently, Scottish officials provided guidance indicating that a transgender woman with a gender recognition certificate would be recognized as a woman.
FWS is now aiming to challenge this definition.

Trina Budge, director of FWS, pointed out, “If the definition of sex is not aligned with its conventional meaning, public boards could potentially consist of an equal split of 50% men and 50% individuals with certificates, yet still comply with female representation regulations.”
A lower court dismissed FWS’s initial challenge in 2022, but the group received consent to escalate its case to the Supreme Court last year.

Aidan O’Neill, representing FWS, articulated during Tuesday’s session that the term “sex” under the Equality Act should refer strictly to biological sex, reflecting the ordinary understanding of the term.
“Our viewpoint indicates that one’s sex—whether male or female—is determined from conception and is rooted in one’s physical being,” he expressed, reaffirming that it represents an “immutable biological state.”

Conversely, organizations such as Amnesty International contend that excluding transgender individuals with gender recognition certificates from specific protections against sex discrimination is at odds with fundamental human rights.
In a formal submission, Amnesty highlighted its concerns over the increasing erosion of rights for transgender individuals both in the U.K. and internationally.
The group noted, “Implementing a broad policy that excludes trans women from single-sex services is not an appropriate means of achieving a valid objective.”

The proceedings are anticipated to span two days, with a ruling expected to be delivered at a future date.