UK Supreme Court to Rule on Legal Definition of ‘Woman’ in Landmark Equality Case

Campaigners from For Women Scotland (FWS) outside the Supreme Court in London

The UK Supreme Court is preparing to deliver a landmark ruling on the legal definition of the word “woman,” following a long-running legal challenge brought by women’s rights campaigners. The decision, due on April 16, will clarify whether individuals with a Gender Recognition Certificate (GRC) identifying as female are legally recognized as women under the Equality Act 2010.

The dispute arose from legislation passed in Scotland—the Gender Representation on Public Boards (Scotland) Act 2018—which aimed to ensure that 50% of positions on public boards are held by women. Campaign group For Women Scotland (FWS) challenged the law, arguing that including trans women—those born male but who have acquired a GRC—undermines the legal protections based on biological sex and could erode sex-based rights.

In 2022, the Court of Session ruled in favor of FWS, stating that the Scottish Government exceeded its legal powers by altering the definition of "woman" in the act. Following the ruling, the Scottish Government removed the definition from the legislation and issued new statutory guidance, stating that the definition of a woman under the 2018 Act matched that in the Equality Act 2010. The guidance also asserted that a person with a GRC recognizing them as female legally has the sex of a woman.

Fiona McAnena, Maya Forstater, Pam Ghosal and Helen Joyce stand outside the supreme court on the day of a ruling on an appeal by For Women Scotland

FWS contested this revised guidance, arguing that "sex" under the Equality Act refers strictly to biological sex, and that redefining it to include those with a GRC went beyond the powers of the Scottish Government. Their challenge was dismissed by the Outer House of the Court of Session in December 2022. The Inner House upheld this decision in November 2023 but granted permission for an appeal to the UK Supreme Court.

During the two-day hearing held last November, the appeal was reviewed by Lord Reed, Lord Hodge, Lord Lloyd-Jones, Lady Rose, and Lady Simler. The panel announced it would take time to carefully consider the matter before issuing a final judgment.

FWS director Trina Budge emphasized that the implications extend far beyond public board appointments. She warned that failing to define sex according to its ordinary, biological meaning could jeopardize the integrity of sex-based rights. According to Budge, public boards could hypothetically be composed of 50% men and 50% men with GRCs, yet still be considered compliant with female representation targets.

Revathi Malesh Thirumalesh and Thirumalesh Chellamal Hemachandran, the parents of Sudiksha Thirumalesh; Dean Gregory and Claire Staniforth, the parents of Indi Gregory; Lanre Haastrup (back), the father of Isaiah Haastrup; Aliya Abbasi and Rashid Abbasi, the parents of Zainab Abbasi; Hollie Dance, the mother of Archie Battersbee and a relative of Pippa Knight outside the Supreme Court in London

Budge further stated that the court’s decision could impact access to single-sex services like hospital wards and public toilets, and influence entitlements such as maternity leave and the rights of same-sex attracted individuals to associate exclusively with members of their biological sex.

Representing the Scottish Government, Ruth Crawford KC argued that the issuance of a GRC constitutes a legal change in status. She maintained that an individual who acquires a GRC "becomes recognized as belonging to, or becoming, the sex of their acquired gender," and that such individuals are entitled to the protections offered under the Equality Act.

The Scottish Government declined to comment on the case while legal proceedings are ongoing.

The Supreme Court’s forthcoming decision is expected to set a critical precedent in the ongoing debate over the legal and societal interpretation of sex and gender in the UK.