“Incredibly sadly, we will have to restrict our membership on the basis of biological sex from April next year,” Green said. “But the message we really want to get across is that it remains our firm belief that transgender women are women, and that doesn’t change.”
https://www.theguardian.com/uk-news/2025/dec/03/womens-institute-no-longer-accept-trans-women-members-april
Tellingly - they still think women can have a penis.