What to wear to interview for a mature student university course?

[DriveMeToTennessee]

I have an interview next week for place on a part time foundation certificate course at a top uni (think Oxbridge). I want to look smart but not over the top- I've worked in offices in my previous jobs and have always dressed in smart office wear for interviews but I don't think office wear would be right for this... Does anyone have any suggestions for what would be appropriate? I'm 28, size 10.... Any ideas are gratefully received!

[familyfarm]

I would wear a smart semi-formal dress but no blazer (it's too hot anyways). You could take blazer with you incase it is more formal.