In a unanimous decision, the UK Supreme Court declared Wednesday that the legal definition of a woman pertains to individuals who are biologically female at birth, thus excluding transgender women.

The court’s five judges determined that the UK Equality Act allows for the exclusion of trans women from certain single-sex spaces and groups. These may include facilities like changing rooms, shelters for the homeless, swimming areas, and medical services exclusively for women.

The judgment specifies that even if a transgender individual possesses a certificate recognizing them as female, they should not be regarded as a woman under the law for equality purposes.

However, Justice Patrick Hodge clarified that the ruling “does not remove protection from trans people,” who are “protected from discrimination on the ground of gender reassignment.”

Hodge stated that defining “sex” as certificated sex would disrupt the definitions of “man” and “woman” and “the protected characteristic of sex in an incoherent way,” further adding that “It would create heterogeneous groupings.”

Women’s rights groups hailed the court’s decision.

Susan Smith, co-director of For Women Scotland, the organization that initiated the case, commented, “Everyone knows what sex is and you can’t change it. It’s common sense, basic common sense and the fact that we have been down a rabbit hole where people have tried to deny science and to deny reality and hopefully this will now see us back to, back to reality.”

According to employment lawyer Hannah Ford, the judgment offers clarity on a contentious issue within the UK. However, she also noted it represents a setback for transgender rights, predicting “an uphill battle” to foster welcoming workplaces for trans individuals.

Ford told Sky News that “This will be really wounding for the trans community.”