According to SEEN in Health, a sex realist NHS staff network, updated NHS single sex guidance is due be published in 2 days.
This should outline who is eligible to be placed on a male/female single sex ward and who is not. If they follow the law this should be determined simply on the basis of (biological) sex.
I imagine there will also be some pragmatic solutions touted for trans-identified patients, such as the use of side rooms, where available and appropriate.
Could this be the start of the NHS following the law and protecting patients when at their most vulnerable?