Do free museums serve all social classes?

Free museum access is often depicted as something that might be classified as a quasi-public good, but this Newsnight clip debates whether or not that's the case.

Are museums the preserve of the middle-class, and does free access simply admit those who are already able to pay? Or do they give the working-class access to culture and generate positive external effects.

This debate is particularly apt for the new Design Museum in Dundee - 1 in 4 children live in poverty in the city. Oh, and there are multiplier effects.