She is now saying the Home Office is working with forces to improve the figures
Yes, but if you read the government's (mad) response to the petition that they posted just last week, they say they don't understand the question because biological sex doesn't exist, and they then go on to say if by biological sex you mean anatomy and chromosomes, then that's unethical to check, so no.
And if you mean sex assigned at birth, then GRC blah blah...and they trail off avoiding answering how they actually record sex for the majority of people who obviously don't have GRCs.
But they link to their transgender policy, which, hidden in footnote 5, reveals that actually they just let everyone self-identify their gender when they arrive at the prison (although presumably they knew whether to deliver them to the male or female prison based on something).
And then if anyone says they're trans, the policy tells them they should look at their hair and their clothes and their mannerisms, any prosthetics, and so on, to decide whether they are in fact a woman or a man on this inside or whether they're just taking the piss. This is all in the Prison Service's trans policy, which would have been mandated by Stonewall.
So I don't see how they are going to even know how to implement Priti's order to record biological sex at this point because they've tied themselves in knots already.
Undoing the current mess isn't as simple as just "stop messing around and record biological sex" - they're in a real pickle at this point.