For Women Scotland v Scottish Ministers: Reaffirming Biological Sex in UK Equality Law

In For Women Scotland Ltd v The Scottish Ministers [2025] UKSC 15, the United Kingdom [UK] Supreme Court held that the term “woman” in the Equality Act 2010 refers to biological sex, excluding transgender women – even those with Gender Recognition Certificates [GRCs] – from single-sex provisions under that Act. This article examines the Court’s reasoning, its statutory and constitutional implications, and the emerging legal and human rights challenges raised by the ongoing appeals to the European Court of Human Rights [ECtHR]. 

A Legal and Political Debate

The intersection of gender identity and statutory definitions of sex has become a legally and politically contested space in the UK. The UK Supreme Court’s April 2025 judgment in For Women Scotland Ltd v The Scottish Ministers marks a watershed in this debate. It represents the first definitive ruling by the UK’s higher court on the legal meaning of “sex” under the Equality Act 2010 – a ruling that affirms a biologically grounded interpretation with immediate ramifications for law and policy across the UK.  

Background and Procedural History

The Scottish Parliament’s Gender Representation on Public Boards (Scotland) Act 2018 aimed to increase the number of women on public boards. In implementing the Act, Scottish Ministers issued guidance interpreting “woman” to include individuals who have obtained a GRC under the Gender Recognition Act 2004. 

For Women Scotland Ltd brought a judicial review, arguing that such an interpretation unlawfully redefined a protected characteristic reserved to Westminster under the Equality Act 2010. The Inner House of the Court of Session initially upheld the guidance, but this decision was reversed on appeal to the Supreme Court. 

Statutory Interpretation: Equality Act v Gender Recognition Act

The Supreme Court’s unanimous decision focused on the primacy of the Equality Act 2010, a reserved piece of legislation under the Scotland Act 1998. The Court held that: – 

• “Sex” in the Equality Act refers to biological sex, not acquired gender. The judges emphasised that Parliament’s use of the term was deliberate, reflecting fixed categories of male and female. 
• GRCs do not override the definition of “sex” for the purpose of the Equality  Act. While a GRC modifies a person’s sex for most legal purposes, it does not extend to sex-based exceptions in the Equality Act unless Parliament explicitly provides otherwise.
• The Scottish Government exceeded devolved authority by attempting to redefine sex-based protections in a manner inconsistent with UK-wide legislation. 

The Court’s reasoning rested heavily on textualist and purposive approaches to interpretation, citing parliamentary debates, statutory definitions, and the legislative scheme of both Acts.

Constitutional Significance

From a constitutional law perspective, the ruling reinforces: 

• The supremacy of Westminster legislation in reserved maters. 
• The limits of devolved governments in modifying legal definitions entrenched in UK-wide statutory frameworks. 
• The judiciary’s role in preserving the coherence of statutory schemes, especially when policy goals challenge legislative competence. 

The Judgment may also set a precedent for future challenges where devolved measures intersect with reserved equality protections. 

Legal and Social Implications

While affirming the protection of women’s spaces based on biological sex, the ruling introduces significant tension into the operation of equality law: 

• Transgender individuals with GRCs may be excluded from legal recognition in contexts such as single-sex services, raising questions about proportionality and fairness. 
• Institutions must now review policies and practices to ensure compliance with a biological definition of “sex”, potentially resulting in legal uncertainty and litigation.
• The decision could invite more restrictive interpretations of trans rights in employment, education, healthcare and sports, despite existing protections under the gender reassignment provisions of the Equality Act. 

The Human Rights Challenge Ahead

On 23 April 2025, a coalition of transgender advocacy organisations filed an appeal to the ECtHR, arguing that the UK’s interpretation violates: – 

• Article 8 ECHR (right to respect for private and family life), and
• Article 14 ECHR (prohibition of discrimination). 

The appeal asserts that denying recognition of trans women as women under equality law constitutes unjustified discrimination and undermines their dignity and autonomy.

While ECtHR decisions are not binding on UK courts in the same manner as domestic precedents, an adverse finding could exert substantial pressure on Parliament to revisit the Equality Act’s definitions or expand its exceptions. 

Watch This Space

The Supreme Court’s ruling in For Women Scotland represents a formalist and textual reaffirmation of statutory categories in UK equality law. While legally orthodox, its implications are far-reaching – both socially and doctrinally. As the UK confronts the evolving relationship between law, identity and rights, this case will likely serve as a keystone for future legal and political developments.