This seems to be a common tactic - go with a slogan. TWAW, then anything that threatens that idea is labelled as ‘transphobic’. Say it a lot, say it like it’s obvious - and then it pretty soon gets accepted as ‘fact’.
Sex-based rights are good obviously, but if you can get in there and say the very statement is a transphobic dogwhistle, you’ve taken control of the narrative. Make sure some teens proudly trumpet that ‘fact’ over social media and you’re laughing. Now every time it’s mentioned, you can triumphantly shout out “Dog whistle! Bigots!”. No matter if it’s crap and makes no sense. You’ve brainwashed some brainless SJWs into shouting it, and it will spread like a fungus.
Sian Berry seems to have a huge amount of dislike for her fellow women. She knows what she’s doing.
I will never vote Green again while this bunch of misogynists are in power. They’re living on another planet. They care more about this idiocy than about climate change. They’re becoming a laughing stock. I’m disgusted with them.