The Supreme Court in Britain ruled on Wednesday that trans women do not fall within the legal definition of women under the country’s equality legislation.

The landmark judgment, which said that the legal definition of a woman is based on biological sex, is a blow to campaigners for transgender rights. It could have far-reaching consequences on the operation of single-sex services like domestic violence shelters, as well as on equal pay claims. And it comes amid intense public debate over the intersection of transgender rights and women’s rights.

However, the five judges involved in the ruling emphasized that they were not commenting more broadly on whether trans women are women, saying it was not the role of the court to adjudicate on the meaning of gender or sex. Instead, the judgment is limited to the precise interpretation of language in the 2010 Equality Act, which aims to prevent discrimination.

The decision will likely be welcome news for Prime Minister Keir Starmer of Britain. Some legal scholars had theorized that the court might refuse to rule and instead force his government to weigh in on a thorny and divisive issue. The government said in a statement Wednesday that it had always supported the protection of “single-sex spaces based on biological sex” and that the ruling brought “clarity and confidence” around the provision of services in hospitals, domestic violence shelters and sports clubs.

What did the court say?

The deputy president of the court, Lord Patrick Hodge, said on Wednesday: “The unanimous decision of this court is that the terms ‘woman’ and ‘sex’ in the Equality Act 2010 refer to biological women and biological sex.”

He added: “We counsel against reading this judgment as a triumph of one or more groups in our society at the expense of another. It is not.” He said that trans people would continue to have protections against discrimination, but that it would be under the protected characteristic of “gender reassignment” rather than sex.