In a landmark ruling on April 16, 2025, the United Kingdom’s (UK) highest court proclaimed that the legal definition of “woman” excludes trans-women, in a case with sweeping consequences for how equality laws are applied.
Britain’s Supreme Court ruled unanimously that the definition of a woman in equality legislation refers to “a biological woman and biological sex,” sparking celebrations outside court among gender-critical campaigners.
The court decided on whether trans women with a Gender Recognition Certificate (GRC) – which offers legal recognition of someone’s female sex – are protected from discrimination as a woman under the nation’s Equality Act 2010.
A group of campaigners in Scotland brought the challenge in 2018, arguing that those rights should only safeguard those assigned as women at birth. But the Scottish government said that a trans-woman with a GRC is legally a woman and should therefore be accorded the same legal protections.
Even though the case draws from a debate over Scottish laws designed to increase the number of women sitting on boards, the outcome on Wednesday will shape the increasingly fractious and polarizing debate over transgender rights across the UK.
The UK’s ruling Labour party said the ruling brought “clarity and confidence” while the opposition Conservatives called it a “clear victory for common sense,” urging the government to amend existing guidance.
“The terms woman and sex in the Equality Act 2010 refer to a biological woman and biological sex,” Lord Patrick Hodge told the court in London. “The provisions relating to sex discrimination can only be interpreted as referring to biological sex,” he added.
“Interpreting ‘sex’ as certificated sex would cut across the definitions of ‘man’ and ‘woman’ and thus the protected characteristic of sex in an incoherent way,” a summary of the ruling said, which added that transgender women could be excluded from same-sex facilities such as changing rooms if “proportionate.”
If transgender women with a GRC are accorded the same protected characteristic as biological women under the Equality Act, Hodge said, they would possess “greater rights than those who do not,” citing provisions relating to pregnancy and maternity leave.
The justice insisted that the court’s interpretation of the Equality Act 2010 “does not remove protection from trans people,” with or without a GRC document. A trans woman could claim discrimination on the grounds of gender reassignment, and because “she is perceived to be a woman,” added Hodge.
The ruling has triggered wide jubilation within and outside court by women activists in Scotland, and the UK at large.
Britain’s government “has always supported the protection of single-sex spaces based on biological sex,” a spokesperson said, following the ruling.
“This ruling brings clarity and confidence, for women and service providers such as hospitals, refuges, and sports clubs,” the spokesperson added. “Single-sex spaces are protected in law and will always be protected by this Government.”
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