Under the equality law, U.K. Judges at the Supreme Court have unanimously ruled that a woman is defined by biological sex.

The court sided with campaign group For Women Scotland, which brought a case against the Scottish government arguing that sex-based protections should only apply to people that are born female.

Judge Lord Hodge said the ruling should not be seen as a triumph of one side over the other, and stressed that the law still gives protection against discrimination to transgender people.

The Scottish government argued in court that transgender people with a gender recognition certificate (GRC) are entitled to the same sex-based protections as biological women.

The Supreme Court was asked to decide on the proper interpretation of the 2010 Equality Act, which applies across Britain.

Lord Hodge said the central question was how the words “woman” and “sex” are defined in the legislation.

He told the court: “The unanimous decision of this court is that the terms woman and sex in the Equality Act 2010 refer to a biological woman and biological sex.

“But we counsel against reading this judgement as a triumph of one or more groups in our society at the expense of another, it is not.”

He added that the legislation gives transgender people “protection, not only against discrimination through the protected characteristic of gender reassignment, but also against direct discrimination, indirect discrimination and harassment in substance in their acquired gender”.

Campaigners who brought the case against the Scottish government hugged each other and punched the air as they left the courtroom, with several of them in tears.

The Equality Act provides protection against discrimination on the basis of various characteristics, including “sex” and “gender reassignment”.

Judges at the Supreme Court in London were asked to rule on what that law means by “sex” – whether it means biological sex, or legal, “certificated” sex as defined by the 2004 Gender Recognition Act.

The Scottish government argued the 2004 legislation was clear that obtaining a GRC amounts to a change of sex “for all purposes”.

For Women Scotland argued for a “common sense” interpretation of the words man and woman, telling the court that sex is an “immutable biological state”.

Speaking outside the Supreme Court following the ruling, For Women Scotland co-founder Susan Smith said: “Today the judges have said what we always believed to be the case, that women are protected by their biological sex.

“Sex is real and women can now feel safe that services and spaces designated for women are for women and we are enormously grateful to the Supreme Court for this ruling.”

First Minister John Swinney said the Scottish government accepted the judgement.

His post read: “The ruling gives clarity between two relevant pieces of legislation passed at Westminster.

“We will now engage on the implications of the ruling. Protecting the rights of all will underpin our actions.”

Conservative leader Kemi Badenoch described the ruling as a “victory for all of the women who faced personal abuse or lost their jobs for stating the obvious”.

She added: “It’s important to be reminded the court strongly and clearly re-affirmed the Equality Act protects all trans people against discrimination, based on gender reassignment, and will continue to do so.”