This has (finally) reached me. The two questions of relevance here are:
3 What gender do you identify with?
and
- do you consider your own gender identity to be different from that associated with your sex as registered at birth.
In both cases there is a prefer not to say option. Can I crowd-source a quick bit of guidance - seems to me like prefer not to say covers my position (gender critical). There is no space for comments.
The only other option seems to be to refuse to fill in the questionnaire but that seems a shame because there are sensible questions in it too (eg are you someone's primary carer?)