J.K. Rowling, the creator of the “Harry Potter” series, was criticized by gay and transgender rights groups on Thursday after she expressed support for a British researcher whose views on transgender people were described by a court as “not worthy of respect in a democratic society.”
The researcher, Maya Forstater, lost her job last year at a think tank in London and filed a lawsuit earlier this year alleging discrimination based on what she called her “gender critical” views, which she has expressed often on Twitter. Among them is the belief, which Ms. Forstater tweeted on Wednesday, that “it is impossible to change sex.”
An employment tribunal in London ruled against her on Wednesday, saying her views were “not a philosophical belief protected” by British law but were instead “incompatible with human dignity and fundamental rights of others.”
“It is also a slight of hand to suggest that the claimant merely does not hold the belief that trans women are women,” the court ruled. “She positively believes that they are men and will say so whenever she wishes.”
Mr. Rowling criticized that outcome and said she supported Ms. Forstater, who did not respond to a message seeking comment on Thursday.
“Dress however you please,” Ms. Rowling wrote on Twitter, where she has more than 14 million followers. “Call yourself whatever you like. Sleep with any consenting adult who’ll have you. Live your best life in peace and security. But force women out of their jobs for stating that sex is real? #IStandWithMaya #ThisIsNotADrill.”
Ms. Forstater’s case was widely reported in Britain but became an international news story because of Ms. Rowling’s tweet — and because of the backlash to it, which was powered in part by longstanding suspicion among some L.G.B.T. advocates that the author held negative views of transgender people.
Much of that suspicion has focused on Ms. Rowling’s social media activity. In 2018, she was criticized for liking a tweet that referred to transgender women as “men in dresses.”
A representative for the author said she’d had a “middle-aged moment” and hit the like button accidentally, according to The Guardian. But some critics viewed incidents like that differently in light of her expression of support for Ms. Forstater.
“Well, she finally said the quiet part out loud,” Jackson Bird, a transgender author, tweeted on Thursday. “This is really heartbreaking for a lot of folks. If Harry Potter is ruined for you, I completely get it.”
Ms. Rowling had not addressed the uproar by Thursday afternoon, and declined an offer from the L.G.B.T. advocacy group GLAAD to have an off-the-record conversation about the controversy, said the group’s spokesman, Mathew Lasky.
Ken Kleinberg, a lawyer for Ms. Rowling in the United States, declined to comment on the episode when reached by telephone on Thursday. Phone calls to The Blair Partnership, which represents her in Britain, went unanswered.
Anthony Ramos, who leads GLAAD’s engagement with celebrities on L.G.B.T. issues, said in a statement that Ms. Rowling had “now aligned herself with an anti-science ideology that denies the basic humanity of people who are transgender.”
On Thursday, Alphonso David, the president of the Human Rights Campaign, the most influential L.G.B.T. advocacy organization in the United States, accused Ms. Rowling of being an anti-transgender fundamentalist and demanded she apologize for her statement.
“J.K. Rowling says she’s opposed to fundamentalism in any form, but she’s promoting a harmful fundamentalism that endangers the L.G.B.T.Q. community — particularly transgender youth,” Mr. David said in a statement. “She should apologize.”