Transgender women will no longer be able to play in women's football from 1 June, England's Football Association announced on Thursday following a major shift in its stance.
The FA said it had updated its policy following last month's UK Supreme Court ruling regarding the Equality Act.
The Scottish Football Association also said on Thursday it would implement a similar ban from the start of its 2025/26 season.
These new rule changes will apply to all women's football at amateur and professional levels in both countries.
The English FA's transgender inclusion policy had been updated just before the Supreme Court ruling, and continued to allow transgender women to play in women's football provided they reduced testosterone levels.
Those rule changes gave the FA discretion on whether to allow a trans woman to play, with consideration given to issues of safety and fairness.
Now, though, the FA has barred trans women completely from the women's game after the Supreme Court, the UK's highest court, ruled the legal definition of a "woman" is based on a person's sex at birth and does not include transgender women who hold a gender recognition certificate.
The Football Association will ban transgender women from women's football in England from next season.
— Sky News (@SkyNews) May 1, 2025
It follows a similar move by the Scottish FA this week after a UK Supreme Court ruling in April that a female is defined by biological sex.https://t.co/GQOcmQ9use
"We understand that this will be difficult for people who simply want to play the game they love in the gender by which they identify, and we are contacting the registered transgender women currently playing to explain the changes and how they can continue to stay involved in the game," the FA said in a statement.
But Natalie Washington, a campaigner at Football v Transphobia, told Britain's Press Association: "The people I know that are talking about this are saying: 'Well, that's it for football for me'.
"Most people clearly don't feel that they can go and play in the men’s game for reasons of safety, for reasons of comfort," added Washington, who said mixed inclusive football was still "in its infancy".
There are no registered transgender women in the professional game across the four Home Nations (England, Scotland, Wales and Northern Ireland).
And the BBC reported the FA saying on Thursday there were fewer than 30 registered among millions of amateur players, with Washington questioning the need of a new policy that would apply to such a small number of fooballers.
"It seems to be largely an academic argument made in television studios and radio studios around the country by people who aren't involved in football," she said.
But Fiona McAnena, director of campaigns at human rights charity Sex Matters, welcomed the FA's new policy.
"The FA has had ample evidence of the harms to women and girls caused by its nonsensical policy of letting men who identify as women play in women's teams," she said.
'KNEE-JERK REACTION'
Meanwhile Seema Patel, an associate professor at Nottingham Law School, queried the speed and severity of the FA's new position after recently completing a report for global football governing body Fifa where she recommended a "more nuanced and collaborative approach" to gender eligibility.
"I am surprised by the decision," said Patel in a statement released to AFP in London.
"It could be argued that it is a knee-jerk reaction and far too soon to come to any conclusions since the (Supreme Court) ruling."
Transgender participation has become a hot issue as different sports try to balance inclusivity with ensuring fair competition.
International governing bodies in a number of sports including cycling, swimming and athletics have tightened policies to effectively ban transgender competitors, in some cases amid fears of possible legal action should a biological woman be injured by a trans competitor.
Sebastian Coe, the president of World Athletics, has been outspoken about "protecting" the female category.
The British track great, a double Olympic 1500 metres champion, made defending women's sport a key plank of his unsuccessful bid to succeed Thomas Bach as president of the International Olympic Committee.
In March, World Athletics said it had introduced a cheek swab test to determine if an athlete is biologically female.
"It's important to do it because it maintains... not just talking about the integrity of female women's sport, but actually guaranteeing it," said Coe.
Donald Trump's administration has said it will only recognise two sexes, male and female, with the US president signing an executive order seeking to ban transgender athletes from participating in women's sports.