This current organisation to some extent replaces the GLC (1965-86), which was abolished by Conservative prime minister Margaret Thatcher on grounds of alleged inefficiency, but also because elected Labour Party members were commonly in the majority, and in particular because of Livingstone's then radical populist policies and spending on social programmes.
The GLA was created to improve the coordination of the various London boroughs, and the Mayor of London's role is to give London a single person to represent it. The Mayor porposes policy and the authority's budget, and makes appointments to the capital's strategic transport and development bodies. The Assembly has powers to scrutinise the Mayor's performance, amend the budget and also make proposals.
The Greater London Authority must be distinguished from the Corporation and Lord Mayor of the City of London, which only controls the square mile of the old city, London's chief financial centre. While the Greater London Authority has a modern constitution, the organisation of the City of London has barely changed since the middle ages, and is mainly controlled by City business interests.