The U.K. Supreme Court is set to rule on a landmark challenge over the legal definition of a woman, with far-reaching implications for sex-based rights and everyday single-sex services.
The U.K. Supreme Court is set to rule on a landmark challenge over the legal definition of a woman, with far-reaching implications for sex-based rights and everyday single-sex services.
The Case at Hand
A 2018 law passed by the Scottish Parliament requires a 50% female representation on the boards of Scottish public bodies. This law included transgender women in its definition of women, sparking a challenge from For Women Scotland (FWS), a women’s rights group. ‘The redefinition of ‘woman’ went beyond parliament’s powers’ , FWS argued, and sought to overturn the guidance issued by Scottish officials stating that the definition of ‘woman’ includes a transgender woman with a gender recognition certificate.
The Argument
Aidan O’Neill, a lawyer for FWS, presented their argument to the Supreme Court judges. He argued that under the Equality Act, ‘sex should refer to biological sex and as understood in everyday language’ . According to O’Neill, ‘sex’ is an expression of one’s bodily reality, determined from conception, and is an immutable biological state.

The Stakes
The outcome of this case could have U.K.-wide consequences for sex-based rights and everyday single-sex services such as toilets and hospital wards. Trina Budge, director of FWS, warned that not tying the definition of sex to its ordinary meaning could lead to public boards comprising 50% men and 50% men with certificates, yet still lawfully meet the targets for female representation.
The Debate
The debate around this issue has sparked a heated discussion. While author J.K. Rowling, who reportedly donated tens of thousands of pounds to support FWS, has been vocal in arguing that the rights for trans women should not come at the expense of those born biologically female, opponents such as ‘Amnesty International have expressed concerns about excluding transgender people from sex discrimination protections’ . ‘A blanket policy of barring trans women from single-sex services is not a proportionate means to achieve a legitimate aim,’ Amnesty said in its brief. ‘It conflicts with human rights and undermines the fundamental principle of equality for all.’
Amnesty International is a global human rights movement that campaigns for the protection and promotion of human rights worldwide.
Founded in 1961, the organization has grown to become one of the largest and most influential human rights organizations globally.
With over 7 million supporters, Amnesty International works to end human rights abuses by governments, armed groups, and other actors.
The organization investigates and exposes human rights violations, advocates for policy changes, and supports activists working on the ground.