Q: Who has more power: The Lord Mayor (David Lewis) or the Mayor (Boris Johnson) in London? What is the difference?
A: It's true that the Lord Mayor of London is a ceremonial position appointed by the Corporation of London, but you should also realise that his remit only extends to the City of London rather than Greater London. The city of London is also known as the square mile. It's the old city from Roman and Medieval times. It a very small fraction of London.