The Guardian has just published this. An extract:

Senior figures in the party – including Jeremy Corbyn and Harriet Harman – are strongly supportive of the clarification in policy. A spokeswoman for Harman, the former deputy leader of Labour, said she backed the affirmation that trans women should be able to stand for all-women shortlists without needing a gender recognition certificate. Corbyn said at the weekend: “The position of the party is that where you have self-identified as a woman, then you are treated as a woman.”

But it is understood some Labour MPs are anxious to make sure that there are some safeguards written into the policies to stop, for example, a men’s rights activist attempting to stand as a woman to test the legalities. [J4MB emphasis. The Labour party is dismissing even the possibility that trans women might be men’s rights activists. Outrageous. So having a penis and testicles, a big bushy beard, and a booming voice – basically, being Brian Blessed – won’t make you ineligible to be on a Labour all-women shortlist, but being an activist on behalf of men will? What bizarre times we live in. Why would a man vote for the Labour party today?]