By Ghazali Ibrahim 
In a landmark decision, the UK Supreme Court has ruled that “sex is binary” and that the terms “woman” and “sex” under the 2010 Equality Act refer exclusively to biological sex, not gender identity.
The ruling, delivered on Wednesday, concludes a seven-year legal battle between campaign group For Women Scotland and the Scottish Government.
The case challenged the Scottish Government’s attempt to redefine “woman” to include transgender individuals with a gender recognition certificate.
In the court’s unanimous judgment, Lord Hodge stated: “The concept of sex is binary, a person is either male or female.”
The justices made it clear that no legal recognition of gender identity can override the biological definitions set in UK law when interpreting the Equality Act.
The decision has ignited fierce reactions across the UK. Gender-critical campaigners, including Harry Potter author J.K. Rowling, hailed the ruling as a victory for women’s rights.
“This ruling protects the rights of women and girls across the UK,” she said in a post praising the legal victory of For Women Scotland.
Helen Joyce, director of advocacy at campaign group Sex Matters, said the court’s declaration was long overdue.
“We were right. These women, these ordinary women saying that sex is material in the Equality Act, they were right.”
However, LGBTQ+ rights organizations condemned the ruling. Stonewall called it “incredibly worrying,” warning of its negative implications for transgender individuals.
Mermaids, an advocacy group for trans youth, said the ruling could be “deeply harmful” and pledged to continue supporting the rights of trans, intersex, and non-binary people.
Amnesty International echoed the concern, acknowledging that while the court reaffirmed some legal protections for trans people, the broader message was troubling.
“There are potentially concerning consequences,” said Sacha Deshmukh, Amnesty’s chief executive.
Despite the backlash, the judgment now sets a legal precedent that affirms there are only two legally recognized sexes in UK law: male and female, and that gender identity does not alter this legal framework.
Meanwhile, this recent judgement exemplifies Donald Trump’s statement on Transgender illegality in the United States, which means that the only acceptable gender is Male and Female.
