The Supreme Court’s ruling on the definition of a woman in equality law has been hailed as “a watershed” moment.
Campaigners who had supported the legal challenge branded the judgment a “victory for biology, for common sense, for reality”.
The court’s unanimous ruling, handed down on Wednesday, concluded the terms “woman” and “sex” in the Equality Act 2010 refer to a biological woman and biological sex.
This means, as the equalities watchdog stated, a gender recognition certificate (GRC) does not change a person’s legal sex for the purposes of the Equality Act.
Baroness Kishwer Falkner, chairwoman of the Equality and Human Rights Commission, said the organisation is “pleased” the judgment addressed “difficulties” it highlighted in its submission to the court.
These included “the challenges faced by those seeking to maintain single-sex spaces, and the rights of same-sex attracted persons to form associations”.
Addressing the provision of single-sex services, the written ruling gave examples including domestic violence refuges, rape crisis centres, female-only hospital wards and changing rooms.
It said: “Read fairly and in context, the provisions relating to single-sex services can only be interpreted by reference to biological sex.”
It added: “It is fanciful (even perverse) to think that any reasonable objection to the presence of a person of the opposite sex could be grounded in (gender recognition certificate) GRC status or that a confidential GRC could make any difference at all.”
The LGB Alliance charity, which had made arguments in the case, said the ruling “marks a watershed for women” and is a “victory for biology, for common sense, for reality”.
Its chief executive Kate Barker said the ruling “absolutely blew… out of the water” the idea that “maybe a man could be a woman and could be a lesbian if he had a (GRC) certificate”.
She added it will cut out a lot of expensive and time-consuming court cases in the future “because it sets a clear precedent”.
She said: “The ruling confirms that the words ‘gay’ and ‘lesbian’ refer to same-sex sexual orientation and makes it absolutely clear that lesbians wishing to form associations of any size are lawfully entitled to exclude men – whether or not they possess a GRC (gender recognition certificate).
“It is difficult to express the significance of this ruling: it marks a watershed for women and, in particular, lesbians who have seen their rights and identities steadily stolen from them over the last decade.”
Fellow campaign group Sex Matters, which had also made arguments in the case, said the court had given “the right answer: the protected characteristic of sex – male and female – refers to reality, not to paperwork”.
Former SNP MP Joanna Cherry, a longtime campaigner on the issue, said she felt “hugely vindicated” by the ruling – but warned it needs to be implemented into everyday practice.
She told the PA news agency outside the court: “Now it’s over to the politicians to make sure that the law is obeyed.
“I’m calling on my former colleague John Swinney, the First Minister of Scotland, and on the British Prime Minister Keir Starmer to respect this judgment and to do what they say that they do.
“They both say they believe in women’s rights and they believe in women’s rights to single-sex spaces. If they mean that then they need to make sure that public policy changes to respect the fact that women means biological women and lesbian means women who are sexually attracted to women.”
She added there will “have to be a sea-change” across the public sector to recognise the law has been clarified in the ruling.
Conservative Party leader Kemi Badenoch said the ruling was “a victory for all of the women who faced personal abuse or lost their jobs for stating the obvious”.
She added: “Women are women and men are men: you cannot change your biological sex.
“The era of Keir Starmer telling us women can have penises has come to an end.”
A UK Government spokesman said the ruling “brings clarity and confidence, for women and service providers such as hospitals, refuges, and sports clubs”.
They added: “Single-sex spaces are protected in law and will always be protected by this Government.”