Twenty years ago, London became the first city in the UK to establish a directly elected mayor, marking the beginning of two decades of local government transformation. Since then the three Mayors of London have shaped the capital, and set a precedent for the creation of similar positions in other English cities.

To discuss the office of Mayor of London – its origins, powers, limitations and future – Andrew Carter is joined by Professor Tony Travers, Visiting Professor in LSE Department of Government, Director of LSE London and co-author of London's Mayor at 20: Governing a Global City in the 21st Century.