medium.com/@anneharperwright/sex-gender-the-nhs-1e8f4e6363a6
They were ALWAYS based upon 'gender'.
The evidence is in NHS documents from 2010.
And the Department of Health were told, by the NHS team, not to tell people wards were segregated by sex, because they knew the policy was based on gender.
But the DOH purposefully used the word sex to the public instead.
We've been deliberately misled.