What does the mayor get to do?

But what will the capital's first directly-elected mayor actually be able to do?

The powers and functions of the mayor and the new Greater London Assembly (GLA) were laid out in the Greater London Act.

• Appointments The mayor gets to choose their own deputy from the 25-member assembly. The deputy would be one of the mayor's advisers, sit on the Metropolitan Police Authority and take over in the event of illness or death.

  The mayor's office is expected to be the central area of policy-making for the Greater London Authority.

  He will have a chief of staff, senior advisers and his own policy units covering all areas. He can also form his own cabinet, and will appoint assembly members to a range of London-wide authorities and boards.

• Financial The assembly will take over existing funding along with its functions. It will have responsibility for spending on police, fire, transport and economic development - a total budget of around £3.3bn at present. The mayor will have responsibility for submitting a budget plan to the assembly approval or amendment.

  But the home secretary can overrule the mayor on the police spending, and step in to set a minimum level if the minister decides the GLA has allocated insufficient funds.

  A London Development Agency will be set up to take over responsibility from central government for the allocation inward investment and regeneration funds.

  The mayor will not be in complete charge of this either: a large proportion of spending on the agency and on Transport for London (see below) will be met by specially earmarked central government grants. Using them for any other purpose will not be permitted.

• Transport The mayor will be responsible for producing an integrated transport strategy and for running Transport for London, the new body that will incorporate London Transport, the Highways Agency's responsibility for trunk roads, the Traffic Director for London, and the Government Office for London's transport activities.

  The mayor will appoint the board of Transport for London, and chair it himself if he or she wishes.

  In time, the mayor will have the power to introduce road-user charging and workplace parking levies.

• Planning The mayor will be responsible for strategic planning, producing a Spatial Development Strategy for the capital. This will replace central government guidance, and will cover housing, retail development, waste management and regeneration.

• Environment The mayor can organise city-wide action to improve the environment. He will be required to produce a four-yearly report on the state of the capital's environment, develop an air quality strategy, a biodiversity action plan, an ambient noise strategy and a municipal waste management strategy.

• Culture The mayor can organise city-wide action on cultural issues including arts, sports and tourism, such as a bid to get the Olympic Games staged in the capital. He will also appoint the Cultural Strategy Group for London, which will advise the GLA.

• Emergency services The mayor will appoint and oversee the London Fire and Emergency Planning Authority, and 12 members of the 23-strong Metropolitan Police Authority.