I have just completed my MChem at Durham and had an offer to do an MRes plus PhD at Imperial College. This required a 2:1, but I got a 2:2 although with good marks for my research project. I could stay on at Durham to do a similar project, but I wanted to get out of here as it's such a small place! However I know that not many other top universities will look at me with a 2:2. Would I be mad to pass up the offer of a PhD at a department like Durham?

Yes I would seriously consider staying in at the same place 2.ii is not good for imperial

A 2(2) leaves you with 2 options really. One is to do an MSc course which involves another year and more money and the other is to work your way t a PhD through relavent experience which takes time, but you get paid.
Or you could stay at Durham, which believe me, is not remote (Not like Keele)

hey! try elsewhere whilst holding on to ur offer in Durham. apply to imperial first & see what they say. don't assume that they will automatically reject you. am in durham myself & i know what you mean when you say you wanna move. stay here only if you have no option or ur sure you could take on 3 more years in Durham!!!!!

try somewhere else but hold on to durham as well