The interview lasted one hour and was conducted by the shop manager and recruitment manager. They were great! They made me feel really comfortable and welcome. They had my CV and cover letter in front of them with lots of notes and overall they were really well prepared and organised. They didn't ask any generic questions (which I really don't like) and basically asked follow-up questions about things I mentioned in the application. About 30m of the interview consisted of hypothetical scenarios type questions. They test your personality, experience and common sense.
I didn't get the job and asked for feedback. They replied rather quickly and were very kind. I didn't have enough sales experience in their view so they suggested volunteering with them and then applying again if possible.
I would definitely recommend applying for a job with the British Red Cross! I was really impressed with the people and the process.