UK Supreme Court to decide if trans women are legally defined as women

A landmark ruling on trans rights could reshape the legal meaning of “woman” across Britain.

A general view of the Supreme Court in London, England, on November 15, 2023. Photo by Leon Neal/Getty Images

By Anna Fadiah and Hayu Andini

Britain’s highest court will issue a highly anticipated judgment on Wednesday that could redefine how trans women are legally recognized under UK law. At the heart of the case is a single question with far-reaching consequences: are trans women legally defined as women under the Equality Act 2010?

The verdict will settle a lengthy legal battle between the Scottish government and For Women Scotland (FWS), a gender critical campaign group. But beyond this court case, the implications could extend to the way sex-based rights are interpreted across the country — from access to women-only spaces to the protections afforded in the workplace.

The stakes are high and the tension is palpable. With the UK grappling with evolving views on gender identity, the judgment could either reaffirm protections for trans individuals or strengthen legal arguments for restricting access to certain sex-based spaces.

The case that could redefine gender rights in the UK

At the core of the legal dispute is how to interpret the term "woman" in British law — a term that might seem simple on its surface, but one that has sparked one of the most intense culture debates in recent years.

The Scottish government, citing both the Equality Act and the Gender Recognition Act 2004, argues that trans women legally defined as women through a Gender Recognition Certificate (GRC) are entitled to full legal recognition as women. This includes protection against discrimination based on sex and gender reassignment.

However, For Women Scotland takes the opposite view. The group insists that sex is immutable and determined solely by biology. According to their position, legal documents like a GRC do not — and should not — override biological sex. In their view, trans women, even with legal documentation, should not be treated the same as women born female under laws meant to protect sex-based rights.

This dispute began with a 2018 Scottish law designed to increase female representation on public boards. The law included trans women with GRCs in its definition of "women," prompting FWS to launch a legal challenge. After losing the case in lower courts, the group appealed to the UK Supreme Court in November.

How the Equality Act and GRCs intersect

The Equality Act 2010 offers legal protection from discrimination on a range of characteristics, including sex and gender reassignment. But it defines a woman simply as a “female of any age” — a definition that opens the door to interpretation.

For the Scottish government, a trans woman with a GRC — issued under the 2004 Gender Recognition Act — is legally female and thus protected under the same provisions as any other woman. Ruth Crawford, the government’s lead lawyer in the case, compared the legal status of a GRC to that of adoption, stating that it is “no more a legal fiction than adoption.”

But Aidan O’Neill, representing FWS, warned the court that such an interpretation could lead to “absurd and unjust consequences.” He urged the judges to base their decision on “the facts of biological reality rather than the fantasies of legal fiction.”

Just under 8,500 people in the UK have received a GRC since 2004, an average of around 420 per year. While the numbers may seem small, the symbolic and legal importance of their recognition as women is immense.

A ruling with deep cultural and political impact

Whatever the verdict, the ruling will inflame passions on both sides of the debate.

For gender critical activists, a judgment in their favor would mark a major legal victory — one they argue is essential to preserving sex-based protections for women. For LGBTQ+ and trans rights advocates, such a result could feel like a rollback of rights and a signal that legal recognition can be rescinded, even with a GRC.

Public figures have already taken sides. Author J.K. Rowling, a vocal critic of gender self-identification, has aligned herself with the gender critical camp and has become a lightning rod for both support and criticism. Her stance has fueled debates far beyond literature, giving cultural weight to an already volatile topic.

The ruling comes as trans rights face increasing political scrutiny around the world. In the United States, Donald Trump’s return to power has led to renewed attacks on what he calls “gender ideology.” His administration has pushed to legally recognize only two sexes, restrict trans athletes, and reduce access to gender-affirming healthcare for minors.

In contrast, the UK under the current Labour government has taken a more measured tone. Labour had pledged to reform gender recognition processes during its campaign, promising to remove “indignities” from the current system. However, since coming into office, the party has de-prioritized those reforms. Trans rights have largely receded from the legislative agenda, raising questions about how much political will exists to address the issue.

What’s at stake for trans women and sex-based protections?

For trans women across Britain, the case goes beyond legal semantics. At stake is the ability to access services and spaces — from domestic violence shelters to changing rooms — without being singled out or excluded. The concern from trans activists is that if trans women legally defined as women lose that recognition, they may face increased marginalization.

For gender critical activists, the case is about preserving spaces they say are designed to protect women born female. They argue that redefining “woman” to include trans women undermines those protections and could expose vulnerable groups to risk.

But many argue the debate is being framed as a zero-sum game, when in reality it reflects a need for nuanced, compassionate policymaking. Striking a balance between rights based on gender identity and those based on biological sex has proven elusive, but remains essential for social cohesion.

Awaiting a decision that could set precedent

The UK Supreme Court’s decision will come at 10:00 a.m. London time. Whatever the outcome, it will likely set a precedent for how British law interprets gender and sex in a modern context.

If the court upholds the Scottish government's view, trans women with GRCs will continue to be recognized as legally female, with access to protections under the Equality Act. If it sides with For Women Scotland, the ruling may limit those protections, creating a legal distinction between sex and gender identity with tangible effects on access to spaces, jobs, and services.

In either case, the ruling is expected to reverberate well beyond the courtroom — influencing not just policy but the broader cultural understanding of gender in 21st-century Britain.

As the nation awaits the judgment, one thing is clear: the question of whether trans women are legally defined as women is not just a legal issue, but a mirror reflecting Britain’s deepest social divisions, values, and aspirations.