I recently sent an email to a prospective supervisor, and he seemed very interested in what I had to say. As a result I have been asked to go to see them next week. However in my email I specified that I was studying for an MSc but didn't say that I only got a lower second in my BSc. Will this supervisor be put off once he finds out that I don't have a 2:1 or a first?

Congrats on the interview, im sure you will do really well. If you have an MSc it doesnt really matter what undergrad degree you have.Im sure he wont be put off!! I have a 2:2 + MSc and i start my PhD this autumn. Remember HE asked to see YOU on the basis of your initiative and not a standard reply to an advert!! Goodluck

He must have liked what he saw so don't worry about it! As long as you can show you are committed and can do the job you're sorted! Good luck.