I too am watching to see him twist this back soon.
This is what has been said by Keir Starmer in the past:
A woman is a female adult, and in addition to that trans women are women, and that is not just my view — that is actually the law. It has been the law through the combined effects of the 2004 [Gender Recognition] Act and the 2010 [Equality] Act. So that’s my view. It also happens to be the law in the United Kingdom.
https://archive.ph/1ZZW5
So I am just waiting for the 'and in addition ...' because I suspect it will be something like: A woman is a female adult, and in addition to that trans women are women in some aspects of the law.
Or something.