This follows from the recent Equalities Act which requires public bodies (including universities) to promote equality between eight 'protected characteristics' (sexual orientation being one); as any analysis of the composition of student bodies has been based on guesswork so far, gathering the data provides for better and clearer analysis to identify any problems.

I see three potential issues with it - first is the right to decline to answer (this has long been the case when asked about race); second is the potential to change this, a significant number of people come-out whilst at university; third is privacy, data protection law is very strict over here but attention needs to be paid to the manner in which the data are gathered as enrolment paperwork is often completed by a new cohort in a room together which much peering over shoulders.

I could see the goals of the law - adopt policies discouraging bullying of LGBT students, access to counseling - being met without the prior name-based disclosure. Disclosure appears to be more about stats...

people declare their race on college enrollment forms. I think this is a good idea so long as its voluntary