As regards who made the announcement, Sky news reports
"Starmer said: “I welcome the decision of the Supreme Court, which has given us clarity, much-needed clarity, and I think for those that are now drawing up guidance, it’s a much clearer position.
"I’m really pleased that the court has now clarified the position.
“We can move on from there and I think that’s been very helpful, and I would welcome that", he told the BBC.
Drawn on whether this means he does not believe a trans woman is in fact a woman, Starmer said: “A woman is an adult female, and the court has made that absolutely clear."
Starmer also suggested guidance needs to be shared to public bodies to ensure all organisations following the ruling.
so I'm not sure about the point made above on who should be breaking the news.