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Mayor of London and London Assembly

The Greater London Authority Act 1999 established the GLA, which encompasses the mayor of London and the London Assembly.

City Hall, Greater London Authority

Why was the Greater London Authority created?

The abolition of the Greater London Council in 1986 left London as a whole without a directly elected government for the first time in almost 100 years. In 1997 the Labour Party came to office with a manifesto commitment to re-establishing an elected tier of government for London, to follow a referendum “to confirm popular demand”.[1]

The Blair government published its proposals to create the Greater London Authority (GLA) in a white paper in March 1998. The confirmatory referendum held in May 1998 approved the establishment of the GLA, with 72% of the vote (on a 34% turnout). The Greater London Authority Act 1999 was subsequently passed, establishing the GLA, which encompasses the mayor of London and the London Assembly. The first mayoral and Assembly elections were held in May 2000.

What are the powers of the mayor of London?

The mayor has certain defined powers across areas including transport, housing, economic development, planning, environment, policing, and fire and rescue. They also set the annual budget for the GLA, subject to approval by the London Assembly.

A central function of the mayor is to oversee Transport for London (TfL). The mayor sets its overall strategy and has the power to set fares for the underground, buses and other TfL services. In this role, the mayor also holds some powers over road usage, including control of the congestion charge and Ultra Low Emissions Zone.

The mayor also acts as police and crime commissioner for London and is therefore responsible for setting the strategic direction and priorities for the Metropolitan Police. Operational decisions remain the responsibility of the Met commissioner, who is appointed by the home secretary following consultation with the mayor. The mayor also sets the Met’s budget in consultation with the commissioner.

The mayor has similar powers over the London Fire Brigade, setting its budget and approving the London Safety Plan. They can also appoint the fire commissioner.

Another important mayoral responsibility is to produce a ‘spatial development strategy’ (known as the London Plan) which features the mayor’s policies relating to development and the use of land in Greater London. The mayor also has a role in allocating funding for housing from central government’s affordable homes programme.[2]

The mayor can also establish mayoral development corporations (MDCs), which are aimed at regenerating specific areas. There are currently two MDCs: the London Legacy Development Corporation, which covers the Olympic Park, and the Old Oak and Park Royal Development Corporation, introduced to develop an interchange station between Crossrail and the HS2 rail line.

The GLA has a general power of competence in promoting economic, social and environment improvements in London.[3] Under this broad power, mayors have used this power to fund programmes and initiatives in areas such as culture, food and energy.[4]

The mayor is also required by law to produce strategies in various other areas, including culture, environment, skills and health inequalities. However, they do not have executive responsibilities over these areas, so are reliant on more informal ‘soft’ powers to deliver their strategies by influencing other public and private bodies.

Another less formal role of the mayor is to act as a ‘spokesperson for London’, both in public debate and in negotiations with central government, for instance to secure additional funding for London.[5]

What are the functions and powers of the London Assembly?

The primary function of the London Assembly is to hold the mayor to account. It scrutinises the postholder’s policies and programmes, as well as their advisors and bodies under mayoral control, through committees that conduct investigations and publish reports.  

The mayor is required to attend Mayor’s Question Time, held in front of the Assembly, 10 times per year. The Assembly also holds confirmation hearings for some mayoral appointments but it cannot veto the mayor's choices.

The Assembly has the power amend or vote down the mayor’s annual budget and mayoral strategies, but to do this it needs a two-thirds majority. However, it has never formally amended a budget.[6]

How are the mayor and Assembly elected?

The mayor was elected by the ‘supplementary vote’ system between 2000 and 2021. Under that system, voters cast two votes: one for their first-choice candidate and one for their second choice. If no candidate gets over 50% first-preference votes, then all candidates except the top two are eliminated. Second-preference votes for the two remaining candidates are added onto their original first choice votes. The candidate with the most votes at this stage wins the election.

However, following the passage of the Elections Act 2022, the mayor will be elected by the first past the post system in future elections.[7]

The Assembly is elected by the additional member system. Under this system, each voter has two votes and is represented both by their constituency and London-wide Assembly members.

The Assembly comprises 25 members. Of these, 14 are elected in constituencies via the first-past-the-post system, and the other 11 are elected on a London-wide basis via ‘party lists’. The London-wide members are elected according to how well the respective parties did across the city. The system also takes into account the number of seats won by each party in the constituency vote, in order to ensure proportionality overall.

What happened in past London mayoral and Assembly elections?

The first mayoral election in 2000 was won by Ken Livingstone, who stood as an independent. In 2004, he was re-elected as a Labour candidate by a slightly narrower margin. The Conservatives’ Boris Johnson succeeded Livingstone in 2008 and won re-election in 2012.

The current mayor is Sadiq Khan, who won as the Labour candidate in 2016 and was re-elected for a second term in 2021. In 2016, he defeated the Conservatives’ Zac Goldsmith on the second round with 57% of the vote, and in 2021 he beat Conservative candidate Shaun Bailey with 55%. On no occasion has a mayoral candidate won over 50% of the vote on the first round, but the candidate that won most first preference votes has always been elected mayor after second preferences were considered.

In London Assembly elections, only Conservative and Labour members have ever been elected on the constituency ballot. Various smaller parties have secured representation via the London-wide ballot.

At the 2021 Assembly election, Labour won 11 seats (two short of a majority), the Conservatives nine, Greens three and the Liberal Democrats two. Labour won one seat less than it did in 2016, while the Conservatives, Greens and Liberal Democrats each gained one seat. UKIP lost the two seats it had won in 2016.

Turnout in London elections has tended to rise over time, from a low of 34% at the first vote in 2000. In 2021, however, 42% of registered voters in London cast their ballots – a slightly lower figure than 2016’s record 46%. The drop in turnout was partly caused by a substantial rise in the number of spoilt ballots.

What is the size of the Greater London Authority budget – and where does the money go?

The GLA has an annual budget for day-to-day spending of more than £13bn. In the 2020/21 budget, over half (£7.1bn) was allocated to TfL. The second largest spending area was policing, with £3.9bn allocated to the Mayor’s Office for Policing and Crime. Other areas of spending included the fire service (£489.5m), the London Legacy Development Corporation (£65.7m) and a total of £1.8bn for mayoral programmes and initiatives including for housebuilding, cultural events and skills training.[8]

The mayor is required by law to prepare a capital spending plan, alongside the budget. Latest plans indicate that the GLA expects to spend an average of £5bn a year on capital projects until 2025.[9] Major projects include Crossrail and delivering the government’s Affordable Homes Programme.


How is the Greater London Authority funded?

The GLA is funded by a combination of central government grants, business rates, council tax, and other fares, charges and sources of income. For 2020/21, the GLA budgeted for such fares, charges and other income sources to raise £6.8bn. Transport for London was expected to account for £6.2bn for this – including fares income (£5.1bn), congestion charge (£255m) and advertising revenue (£160m).[10],[11]

The mayor can also raise money for the GLA through the Community Infrastructure Levy, a charge payable on a per-square-metre basis on new developments in London. In 2019/20, the levy raised £135m, and since its introduction in 2012 it has raised £743m.[12] The levy is currently being used to finance Crossrail.

Central government also fund elements of the GLA via direct grant. For example, the GLA receive a core police grant from the Home Office. In total, grants from central government for day-to-day spending amounts to around £3bn.[13]

Since 2013 the GLA has participated in the Business Rates Retention Scheme, enabling it to retain 20% of any increase in business rates revenue. More recently, Greater London has been permitted to retain greater portions of retained rates; in 2020/21, the GLA received a 37% local share.[14] This brings in £2.5bn in revenue.[15]

Londoners pay a council tax precept – collected by London’s boroughs and the City of London Corporation – which helps to fund the services delivered by the GLA and its functional bodies. The level of the precept is determined by the mayor’s budget. In 2020/21, the precept delivered £1bn to the GLA.[16]

The GLA and its functional bodies can borrow money, within limits subject to the Prudential Code – a framework aimed at ensuring the capital spending of local authorities is affordable.

How have the powers of the Greater London Authority changed over time?

Westminster has conferred further powers upon the GLA since its creation in 2000. For instance, in 2007, the mayor was granted additional powers to intervene in planning applications of “potential strategic importance” across all London boroughs.[17] In 2011, the mayor gained further powers over housing and policing.[18]

More recently, there has been some limited devolution in the areas of justice and health and social care.[19],[20] In 2019, responsibility for the adult education budget (£332m in 2020/21) in London was transferred from central government to the mayor.[21]

Successive mayors have asked central government to devolve more powers to the GLA. In particular, two reports published in 2013 and 2017 by the London Finance Commission – a group of experts assembled by the mayor – have made the case for the devolution of council tax, business rates, stamp duty, capital gains tax, air passenger duty, and shares of income tax and VAT.[22],[23] These proposals were not accepted by the UK government, with the partial exception of the capital retaining a higher share of business rates.


[1] New Labour, Because Britain Deserves Better, election manifesto, 1997

[4] Sandford, M, The Greater London Authority, House of Commons Library, 7 June 2018,

[5] Bogdanor, Vernon, Beyond Brexit: Britain’s Unprotected Constitution, 2019

[6] Centre for London, How the London Assembly scrutinises the Mayor, 18 January 2021,

[8] Greater London Authority, The Greater London Authority Consolidated Budget and Component Budgets for 2020-21,, p.84

[9] Greater London Authority, The Mayor of London’s Capital Spending Plan 2021-22,, p.5

[10] Greater London Authority, The Greater London Authority Consolidated Budget and Component Budgets for 2020-21,, p.44

[11] Note: the effects of COVID-19 meant that the fares income collected by TfL in 2020-21 was significantly less than budgeted.  

[12] Greater London Authority, Community Infrastructure Levy Annual Return Overview,

[13] Greater London Authority, The Greater London Authority Consolidated Budget and Component Budgets for 2020-21,, p.85

[14] Greater London Authority, The Greater London Authority Consolidated Budget and Component Budgets for 2020-21, March 2020,, p.68

[15] Greater London Authority, The Greater London Authority Consolidated Budget and Component Budgets for 2020-21,, p.85

[16] Greater London Authority, The Greater London Authority Consolidated Budget and Component Budgets for 2020-21,, p.83

[18] Sandford, M, The Greater London Authority, House of Commons Library, 7 June 2018,

[19] Working Towards Justice Devolution to London, March 2018,

[21] Greater London Authority, Mayor urges government to devolve more adult education funding,

[23] London Finance Commission, Devolution: a capital idea, January 2017,

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