Sir Keir Starmer has insisted that “a woman is an adult female” as he hardened his stance on gender.

The Labour leader insisted that biological women needed single-sex spaces as he ruled out introducing self-identification for changing gender, saying he would retain a requirement for medical diagnosis.

Starmer also backed expansion of London’s Ulez scheme, despite blaming it for Labour’s unexpected defeat in last week’s Uxbridge by-election, instead arguing for greater financial help for those affected.

At Labour’s national policy forum this weekend, the party formally ditched a policy of self-identification which would have allowed people to change their legal gender without the need for a medical diagnosis.

Starmer cited controversy over the Scottish government’s law introducing self-identification, which was blocked by Rishi Sunak