The UK Supreme Court ruled on Wednesday that British equality law defines a woman as an individual who was born biologically female.

"The terms 'woman' and 'sex' in the Equality Act refer to a biological woman," Supreme Court Justice Patrick Hodge said.

Five Supreme court judges unanimously passed the judgement. 

The ruling states that a transgender woman with a Gender Recognition Certificate (GRC) identifying them as female is not considered a woman under UK's equality law.

The case originated from a 2018 Scottish law passed by the Scottish Parliament, requiring 50% female representation on public boards, which included transgender women in its definition of women.

Wednesday's ruling "does not remove protection from trans people," who are "protected from discrimination on the ground of gender reassignment," the top UK court said. 

What was the case about? 

A group called For Women Scotland (FWS) had challenged the 2018 Scottish law, arguing that the redefinition of "woman" is beyond devolved Scottish parliament's powers. 

Scottish officials then issued new guidelines which stated that the definition of a woman included individuals with a Gender Recognition Certificate (GRC).

FWS then claimed the ruling could impact sex-based rights and single-sex spaces such as toilets, hospital wards, and prisons, across Scotland, England, and Wales.

"Today, the judges have said what we always believed to be the case: that women are protected by their biological sex," said FWS co-founder Susan Smith.

The Scottish court rejected the challenge in 2022, but the group was allowed to appeal to the Supreme Court last year.

Rights groups condemn ruling 

Amnesty International filed a court brief expressing concern over the declining rights of trans people in the UK and globally.

The group argued that removing sex discrimination protections for transgender people violates human rights laws.

"A blanket policy of barring trans women from single-sex services is not a proportionate means to achieve a legitimate aim," said Amnesty International.  

LGBTQ charity Stonewall said on Wednesday that the ruling was "incredibly worrying for the trans community."

"Stonewall shares the deep concern at the widespread implications for today's ruling from the Supreme Court," said Simon Blake, CEO of the UK-based charity.

Edited by: Zac Crellin