JK Rowling has been accused of bigotry after she tweeted support for an academic who was forced from her job for saying men cannot 'turn into' women.

Maya Forstater, an internationally renowned expert on tax avoidance was sacked by London office of the Centre for Global Development (CGD) think tank for having 'offensive and exclusionary views' about trans people.

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She subsequently took her employers to an industrial tribunal arguing that it was dangerous to prevent people from holding the belief that while someone is free to identify as the gender they wish, being a female or male is a biological fact not a feeling.

Her case, in which she argued this should be a protected belief under equality law was backed by the Index Against Censorship, but yesterday the tribunal ruled that her dismissal was lawful.

Ms Rowling reacted to the ruling, tweeting: " Dress however you please. Call yourself whatever you like. Sleep with any consenting adult who will have you. Live your best life in peace and security. But force women out of their jobs for stating that sex is real?"

She added: "#IStandWithMaya"

The author, who hasn't tweeted since September, provoked a hugely polarised reaction by wading into the vexed debate over whether women's rights are being compromised by 'pro-trans' polices. 

Some readers complained that she was turning her back on 'the LGBT community' while others thanked her for her intervention.

One Twitter user commented: "The saddest thing is that the woman who inspired millions of kids to be good to each other, include each other despite our differences and stand up against those who would oppress us - is now a bigot herself."

Others said they felt betrayed after loving her books as children.

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But supporters responded: "Her tweet said be yourself. Be who you are. Be who you want to be...those are messages of support for everyone. And nothing at all wrong with stating that you can't change your biological sex. The most basic fundamentals of science confirm this," one wrote.

However, Dr Debbie Hayton, a transwoman, said "magical thinking" was not helpful to the trans movement, and that the author knew the difference between reality and magic.

They said: "There are two sexes and we belong to one or the other. After fathering three children, I am definitely male. I did used to think that I was some sort of woman but only when I cast off such "magical thinking" did my mental health fully recover."