It was May's plan to introduce gender self-ID that galvanised such a strong and rapid response against it, largely coordinated on Mumsnet, within its Feminism and Women's Rights (FWR) subforum.
In fact, the recent UK Supreme Court case which resulted in a ruling that references to "sex", "woman" and "man" in the Equality Act refer to biological sex (as in, a person's sex observed at birth), was brought by a small group of women who met on FWR.
More generally, I think much of the reason that the UK has been so successful in resisting and reversing policy that prioritises self-declared gender identity over sex is that we have a strong tradition of women's advocacy for single-sex provisions, that has been pursued regardless of other political affiliations.
In fact, the recent UK Supreme Court case which resulted in a ruling that references to "sex", "woman" and "man" in the Equality Act refer to biological sex (as in, a person's sex observed at birth), was brought by a small group of women who met on FWR.
More generally, I think much of the reason that the UK has been so successful in resisting and reversing policy that prioritises self-declared gender identity over sex is that we have a strong tradition of women's advocacy for single-sex provisions, that has been pursued regardless of other political affiliations.