When I've interviewed for theatre staff (I'm not sure if you're NMC or HPC) but you might want to think how you'd answer questions like - talk through an emergency situation in theatre, what you did, what was your role, is there anything you'd do differently next time; talk me through a mistake you've made and what you learnt from it (good to know how candidates reflect etc.); have you been in a situation where you have had to challenge a surgeon/anaesthetist, what did you do, what was the outcome; tell me about two of your strengths and one weakness; what learning needs will you have if you are offered the role.
I just recently began working in the NHS after being in the private sector, they were apparently impressed with my knowledge of care pathways, 18 week targets etc. I think if you're coming from the private sector they expect you to not know this so being well researched shows you've thought through the implications of working in the nhs.
Have a google of the six Cs. Care, compassion, etc. currently an nhs hot topic. They might ask you what you know about the keogh review, Francis report. Just been able to say that you know they relate to a breakdown in care at certain hospitals and that its something which could happen again. But hopefully with good staffing, good training focusing on the six Cs it wouldn't happen again.