A woman who lost her job after claiming people cannot change their biological sex has won a landmark appeal against an employment tribunal.

Maya Forstater, 45, lost her job as a tax expert at the Centre for Global Development in March 2019 after she was accused of publishing “offensive” tweets questioning government proposals to allow people to self-identify as the opposite sex.

Her legal dispute against her former employer was seen as a test case on whether a “gender critical” view – meaning a belief that there are only two biological sexes – can be a protected philosophical belief under the 2010 Equality Act.

She originally lost her employment tribunal in December 2019, with an employment judge ruling that there was no legal right to question whether a trans-gender person is a man or a woman.

But that ruling was overturned on Thursday morning. In his  judgment, Mr Justice Choudhury said he acknowledged "some trans persons will be disappointed by this judgment".

But finding in favour of Ms Forstater, he added that he did "not agree" that it would "create a ‘two-tier’ system between natal women and transwomen, with some transwomen fearing that it will give licence to people seeking to harass them".