The socialist politician pledged that Labour would support any government attempt to change the law.
Speaking at a meeting hosted by Pink News to mark the 50th anniversary of the partial decriminalisation of homosexuality in England and Wales, Corbyn said there must be a particular effort to advance trans rights.
The Conservative government’s deal with the socially conservative Democratic Unionist Party means the prime minister could struggle to push through reforms to the Gender Recognition Act without opposition backing, The Guardian said.
Corbyn said May would have his support if she scrapped the requirement for trans people to undergo medical tests, and instead allowed them to self-identify their gender, saying legislation could be passed with Labour backing if the Tories and DUP had a free vote.
“Discrimination has gone on too long. The Gender Recognition Act does not allow trans people to self-identify their gender and forces them to undergo invasive medical tests. This is wrong,” he said.