The London Assembly comprises of 25 elected members elected for by London residents.  Currently the assembly has 11 Conservative, eight Labour, three Liberal Democrat, two Green Party and one BNP Members and is chaired by Darren Johnson (Green Party). The 25 members are elected once every four years, at the same time as the Mayor. There are 11 Londonwide members representing the whole of the capital and 14 constituency members representing constituencies made up of two or three London boroughs.

The Assembly has two main areas of responsibility - holding the Mayor to account and looking at the issues that affect London.  It examines the activities of the Mayor (currently Boris Johnson), directly questioning him and his advisors on strategies and decisions in areas such as transport, housing, economic development, environment, health, planning, public services, the development of places and spaces, culture, sport and tourism.

The Assembly also examines the Mayor's spending and can amend his total budget when two-thirds of the members agree to do so.

The Assembly investigates issues on behalf of London and Londoners in order to help achieve improvements for the city. It publishes the findings and recommendations and makes proposals to the Mayor and other organisations that have an impact on London life.