A British idiom describing ordinary people?

Could anyone help me find a phrase/idiom which is used to describe an ordinary person? I remember it's something like 'a man on ___ bus'. I read it several weeks ago in the Economist or the Guardian, but I can't remember exactly.

You are thinking of the man on the Clapham omnibus. In British law he is a hypothetical, reasonably educated, ordinary person you use to compare expected conduct or behaviours with when dealing with things like negligence.

Source: Too much time in the law library while my wife was in law school, and Wikipedia

If you need it more colloquial:

• Joe Bloggs (UK)
• John or Jane Doe (US)
• the general public
• grassroots
• rank-and-file

If you want to be a bit condescending (hey, sometimes we all do):

• The proletariat
• Hoi polloi
• common people
• Plebs