Girlguiding and the Women’s Institute have said the move followed a top court ruling on biological sex

FILE PHOTO. ©  Guy Smallman / Getty Images

Two of Britain’s biggest organizations for women and girls, Girlguiding and the Women’s Institute, have said they will no longer accept transgender members, citing a court ruling on biological sex.

Girlguiding, Britain’s equivalent of the Girl Scouts, said in a statement on Tuesday that “trans girls and young women will no longer be able to join” the organization. The Women’s Institute, which is more than 110 years old, followed suit on Wednesday, announcing that it will “restrict formal membership to biological women only.”

Both organizations said the changes were not their preferred option but were prompted by the risk of legal action following the UK Supreme Court’s April ruling. The court said that the term “woman” refers to biological sex, not gender identity.

The ruling followed a challenge by For Women Scotland to a Scottish Government measure on women on public boards, which included transgender women with legal recognition as female. The group asked the court to confirm that “woman” means a biological female.

 

READ MORE: UK supreme court rules on definition of ‘woman’

The court stated that “the terms ‘women’ and ‘sex’ in the Equality Act 2010 refer to a biological woman and biological sex,” adding that interpreting sex to include acquired gender “would lead to incoherence” in provisions protecting women on the basis of pregnancy, maternity, and other sex-specific criteria.

A poll conducted shortly after the decision found that a majority supported the ruling, with 59% agreeing that a transgender woman is not legally a woman, according to Electoral Calculus. British author J.K. Rowling, one of the most prominent supporters of For Women Scotland, also hailed the decision.

Earlier this year, the England Football Association said it would change its rules, stating that “transgender women will no longer be able to play in women’s football in England,” with the policy implemented from 1 June 2025. British Rowing has also barred transgender and non-binary athletes assigned male at birth from its women’s racing category, saying that only athletes “assigned female at birth” can compete, while others may enter an Open category.

Recent reports have said the IOC is moving closer to banning transgender women from female Olympic events.