"The Concept of Sex is Binary, a Person is Either a Woman or a Man"

"[The terms] woman [and] sex [in Britain's 2010 Equality Act which bans sex discrimination at work and in society], refer to a biological woman and biological sex."

"[It would make] no sense [for conduct under the Equality Act to be regulated] by reference to categories that can only be ascertained by knowledge of who possesses a [confidential] certificate."

"[The definition of a] woman] under Britain's gender equality law is based on a person's sex assigned at birth]."

"[The definition of sex] in the Equality Act makes clear that the concept of sex is binary, a person is either a woman or a man. [Provisions of the Act that refer to protections for women] necessarily exclude men". 

Supreme Court of the United Kingdom

 

"[The issue of legally defining sex] has been a battleground [and as a result the ruling will probably be seen as] very symbolic, very significant."

"But in some ways, it's quite a specific judgement turning on a particular point of statutory interpretation."

"We'll have to wait and see what the wider symbolic political ramifications [are]."

Colm O'Cinneide, professor of constitutional and human rights law, University College London

For Women Scotland's Susan Smith and Marion Calder celebrated outside court after their appeal was upheld.  Dan Kitwood/GettyImages

 

This was a unanimous ruling by the Supreme Court of the United Kingdom, announced on Wednesday. Commenting on the ruling's narrow but "important" implications, professor of constitutional and human rights law Colm O'Cinneide warned that it could affect transgender people's access to specific single-sex services and spaces in the country.

 

 The LGB Alliance advocates for rights of lesbians, bisexuals and gay men, an intervenor in the case as a third party, celebrated the ruling as "a watershed for women and, in particular, lesbians who have seen their rights and identities undermined over the last decade."

 

The advocacy group For Women Scotland responsible for filing the case, stated on social media that its members were "absolutely jubilant". Formed in 2018, in responding to plans by the government of Scotland to give ease to the legal change of one's gender identity through the elimination of a requirement for a medical diagnosis for dysphoria, the group has now seen its campaign through to fruition to their great satisfaction.

 

 Campaigners celebrate on Wednesday, after Britain's top court delivered unanimous judgement that the definition of a woman under equality law refers to "biological sex."

Henry Nicholls/AFP/Getty Images

Reading out the judgement, the five-member court's deputy president Patrick Hodge took care to counsel against the interpretation of the ruling "as a triumph of one or more groups in our society at the expense of another" -- as, for example, challenging the rights of people assigned female at birth against those of transgender women. Transgender people see protection from discrimination under the Equality Act in other ways; the court's ruling was to prevent that statute from incoherent language undermining its purpose.

 

A complaint had been filed by For Women Scotland in 2022, challenging guidelines on the recognition of transgender people that the Scottish government issued ... which gave rise to For Women Scotland Ltd. v. The Scottish Ministers. A law requiring equal opportunities for women on public boards -- that people issued with a gender recognition certificate (GRC) identifying them as women -- led to the guidelines prompted by a successful legal challenge that the GRC identifies holders as women who should be considered so, for Equality Act purposes. 

These are official documents issued by the British government to a  transgender individual for legal recognition of their gender identity where a Gender Recognition Panel comprised of legal or medical experts evaluates applications. With a GRC people can update their British marriage or civil partnership certification. Only adults diagnosed with gender dysphoria or who have had gender-affirming surgery and lived that gender role for two years are eligible, with the intention of living in the gender for the rest of their lives.

 

The argument For Women Scotland fielded was that the Equality Act protections for women should apply to those whose assigned sex at birth is female, only. People who undergo gender-affirming surgery are provided with specific protections under the act. The group had no intention of altering those protections, but argued that "for women to have full rights and protection it is important that 'sex' is clarified as referring to biology".  

Women's rights activists hold placards outside the U.K. Supreme Court to challenge gender recognition laws, in London, Wednesday, April 16, 2025. (AP Photo/Kin Cheung)

 

"This ruling brings clarity and confidence, for women and service providers such as hospitals, refuges, and sports clubs."

"Single-sex spaces are protected in law and will always be protected by this government."

British government statement