A judge has ruled a legal challenge against rules allowing trans people to use the single-sex facilities at a London swimming pond cannot go ahead at the High Court. Sex Matters took legal action against the City of London, which operates the men’s, ladies’ and mixed bathing ponds in Hampstead Heath, north London. However, Mrs Justice Lieven dismissed the challenge saying the "appropriate forum" for the claim is the county court, as opposed to the High Court. The decision comes after the Supreme Court ruling last year, which said that a person’s legal sex is the one they were biologically assigned at birth. He said the City of London should change its policy after the Supreme Court ruling.