This blog post considers the Supreme Court’s decision in For Women Scotland Ltd v The Scottish Ministers [2025] UKSC 16, handed down on 16^th April 2025.

The central question for the Supreme Court was whether references in the Equality Act 2010 (‘EA’) to a person’s ‘sex’ are to be interpreted in the light of section 9 of the Gender Recognition Act 2004 (‘GRA’) as including people who have a gender recognition certificate. The court held that ‘sex’, ‘man’, ‘woman’ and similar terms in the EA refer to ‘biological sex’. Under the EA, a person with a gender recognition certificate does not qualify as having the ‘sex’ given in the certificate.

To be generous to the Supreme Court, it was faced with bad statutory regimes. The GRA and the EA are out of date. It is also clear that they were not drafted with sophisticated knowledge about gender. Even accepting those difficulties, the court’s reasoning has significant deficiencies. This blog post considers four major problems within the court’s analytical framework: (1) the references to ‘policy’; (2) the reliance on ‘biological sex’; (3) the attempt to mitigate the consequences for transgender people; and (4) the court’s own intellectual expertise.

Problem 1: ‘Policy’

From the start of its judgment, the Supreme Court is at pains to tell us it is not the court’s role ‘to adjudicate on the arguments in the public domain on the meaning of gender or sex’ (at [2]). Its role is ‘more limited’ and ‘does not involve making policy’.

In doing so, the court stumbles on more general problems about ‘policy’. It has whatever meaning we wish it to have or none at all. It offers little precision or clarity. In the judgment, for example, ‘policy’ sometimes seems to mean difficult decisions about how we address discrimination and resolve injustice. The Supreme Court defines its ‘task’ in opposition to ‘policy’: it seeks policy-free statutory interpretation. Yet, later, the court reasons that a provision ‘must be carefully considered in the light of the wording, context and policy of the statute in question’ (at [108]). The judgment then spends page after page wading into questions about ‘single-sex spaces’ and sports. Are these not issues of ‘policy’, albeit in a statutory context?

Problem 2: ‘Biological Sex’

The Supreme Court reasons that ‘biological sex’ describes ‘the sex of a person at birth’ (at [7]). The concept takes on an analytical centrality in the rest of the judgment.

‘Biological sex’ is not a phrase that appears in the EA. It is never clear in the Supreme Court’s judgment what its definition of ‘biological sex’ is. The court refers to ‘sex … at birth’. Is this about hormones, chromosomes, genitals, a combination?  Although it is familiar, ‘sex’ is still a term that needs analytical precision. There are people who, from birth and over the course of their life, do not fall neatly within a ‘sex’ category. The Supreme Court makes no reference to these people. It also makes no mention of intersex people, for instance. Instead, the court proceeds on the unscientific assumption that ‘biological sex’ is a tidy division into which everyone falls.

If given the opportunity, the judges might respond to this criticism by suggesting that it is not for them to define the phrase. That would be an unsatisfactory response, given that the phrase occupies a fundamental role in the court’s reasoning. If the court is so concerned with ascertaining ‘coherent and predictable’ meaning, it should adopt the same approach to its key phrases. This is a basic lesson for lawyers: even the most senior judges should question their own assumptions, especially when they never set out exactly what they are assuming.

Problem 3: Mitigation

For a policy-averse court with a limited role, the judgment spends a lot of time mitigating. Paragraphs 248 to 262 seek to explain why trans people still receive significant legal protection and why, actually, the court’s judgment is not as important as headlines will herald it to be.

In this respect, the court reflects Gorsuch J’s reasoning in the US Supreme Court’s decision in   Bostock v Clayton County (2020) 590 US 644. In that judgment, Gorsuch J reasons that a man who is sexually attracted to another man can claim protection based on sex under Title VII of the Civil Rights Act 1964 if he is treated negatively because that treatment is based on his being a man, whereas a woman attracted to men would not be treated in that way (e.g. pp 9-10).

The reasoning gets us to the right place in the end. Its route is unconvincing, though. We do a conceptual dance to avoid the ideas of sexuality and gender. In FWS, the UK Supreme Court does a similar dance: trans people are protected from direct discrimination based on sex because ‘[a] man who identifies as a woman who is treated less favourably … because of being perceived as being a woman’ can ‘claim for direct sex discrimination on that basis’ (at [253]). There is no ‘practical disadvantage’ or ‘discordance … between the individual’s position in society and the ability to claim on this basis’.

Understood: a trans woman can claim under ‘sex’ because she is, really, a man being perceived as a woman.

Problem 4: Intellectual Expertise

The Supreme Court is not oblivious to its place in these broader conflicts. It deploys a section on ‘terminology’; it repeatedly retreats into its ‘policy’-free role in statutory interpretation; and it spends five pages telling us why the decision will not be so bad for ‘members of the trans community’ after all. This may well be benevolently intended. However, insisting on the idea of being ‘policy’-free and then engaging in much the opposite is as unhelpful as ever. The same goes for a simplistic division between (social) ‘gender’ and (biological) ‘sex’, reminiscent of a lesson in GCSE psychology in 2012. For example, by recognising ‘sex’ discrimination only if it matches features of ‘biological sex’, we miss a lot of nuance about how societies gender a large variety of behaviours and bodily characteristics.

It may be that this judgment is another illustration of bigger problems of the UK’s highest court: contradictory references to ‘policy’ and over-representation of former commercial barristers, who spent their careers addressing starkly different topics, attempting to reason through complex questions of social and cultural importance. But, if a compelling reason we give respect to the Supreme Court is because of its intellectual expertise, it should do better than this.