The ruling was a blow to trans rights advocates and cheered by For Women Scotland, which filed the case. The government said it “brings clarity and confidence.”

The decision clears legal ambiguity and confirms that single-sex services for women such as refuges, hospital wards and sports can exclude trans women.

The terms “woman” and “sex” in the Equality Act refer to a biological woman and biological sex, the Supreme Court has ruled. Campaign group For Women Scotland (FWS) brought a series of challenges – including to the UK’s highest court – over the definition of “woman” in Scottish legislation mandating 50% female representation on public boards.