None. They actually ask very normal and basic questions to which you should not reply honestly as they keep the very British attitude of "play the game" and pretend everything is just wonderful. If this is not your approach they'll not even listen to what you have done until now and what you can offer to them. They'll literally stop the interview with a brief thank you. Advice: Instead of preparing on the company or your cv, just make sure to have the right connections and recommendation inside TA. One of my ex colleagues got a CPC job there (although she has no experience at all in the area and the job is very technical) just by knowing the right person in that team, person who has influence on the decision making of the hiring process.