Thanks for the explanation, IWanttoRetire. So if I've understood corretctly, the GRA phrase "for all purposes" originally meant "for all purposes".
But later, the authors of the Equality Act decided to override the "for all purposes" phrasing of the GRA by creating single-sex exceptions applied on the basis of biological sex.
That part seems clear, if a bit daft.
But Lady Haldane, as I understand it, has said that "for all purposes" also applies to the Equality Act, and that when the Equality Act says "sex" it means "legal sex", not "biological sex".
So where do we draw the conclusion that the single-sex exemptions in the Equality Act apply on the basis of biological sex, not legal sex?
I'm not trying to be difficult, by the way, I just don't understand.