There are 10 contenders in the race to be mayor of London. Here is a guide to the candidates who will be on the ballot paper on Thursday, 1 May.
KEN LIVINGSTONE - Labour
Ken Livingstone has been mayor of London since the job began in 2000 and is trying to secure his third term in office.
The 62-year-old was leader of the Greater London Council from 1981 to 1986 and has had a colourful political career.
Mr Livingstone was a left-wing Labour MP but he left the party in 2000 to fight for the mayoralty after Frank Dobson was chosen as the official candidate.
By the last election, in 2004, he was back within the fold.
He has promised to cut youth murders, saying he has a track record in reducing crime, and has launched five joint "green" pledges with Green Party candidate Sian Berry.
BORIS JOHNSON - Conservatives
Conservative MP Boris Johnson has one of the highest profiles at Westminster, having also been a regular guest on TV shows and editor of the Spectator magazine.
The 43-year-old has spoken of his desire to get London moving and to make improvements to public transport.
He has also stressed his passion for cutting crime, wanting to end the violence which, in his view, blights some of London's communities.
Mr Johnson is a keen cyclist and has been a culture and higher education spokesman for the Conservatives since becoming MP for Henley in 2001.
BRIAN PADDICK - Liberal Democrats
Brian Paddick made headlines as the Metropolitan Police commander in the borough of Lambeth, where he pioneered a "softly-softly" approach to drug possession.
Later in his career he also hit the headlines after questioning the force's response to the Stockwell tube shooting.
Mr Paddick, who turns 50 on 24 April, retired from the force last year, after three decades as a policeman.
He has promised to put extra police officers on the streets, make London's buses more reliable and provide additional affordable housing.
GERARD BATTEN - UK Independence Party
Gerard Batten was a founder member of the UK Independence Party in 1993.
He has gained attention as an MEP through his annual audit of the amount of money which the European Parliament costs the UK.
And before entering politics, he was a salesman for BT for nearly three decades.
"Justice and common sense" are promised by the 54-year-old.
LINDSEY GERMAN - The Left List
Lindsey German came fifth in the 2004 race and is representing The Left List, which was part of the anti-war Respect coalition at the last mayoral election.
She is the convener of the Stop the War Coalition and has been vocal in her desire to withdraw British troops from Iraq and Afghanistan.
Ms German also argues that Londoners should not subsidise the Olympic Games in 2012.
She has said she would work to discourage the use of cars by providing a greater amount of "decent and cheap" public transport.
RICHARD BARNBROOK - British National Party
After campaigning about levels of immigration in east London, Richard Barnbrook was one of 11 BNP councillors to be elected on to Barking and Dagenham Council two years ago.
The 47-year-old has promised "straight-talking" during his campaign for the mayoralty.
Mr Barnbrook opposes the London Olympics and says he would "offer them to Athens" if he wins the election.
He would block the construction of mosques, ban Islamic face veils in public buildings and abolish the congestion charge introduced by Ken Livingstone.
SIAN BERRY - Green Party
Cuts to the cost of off-peak bus and tube journeys form a key element of Sian Berry's manifesto for the Green Party.
Aged 33, she has also pledged free insulation for every home which needs it, plus affordable housing and a higher minimum wage in the public sector.
She was a founder of a campaign group protesting about the use of four-wheel drive vehicles, the Alliance Against Urban 4x4s, which handed out fake "parking tickets" to drivers.
And she has also pushed for more creative use of the land around King's Cross station.
ALAN CRAIG - Christian Choice
Alan Craig, 62, left behind a career in business management when he became a Christian in his late twenties.
He worked with young offenders in east London and this reinforced his belief that the family had a major role to play in a cohesive society.
More faith-based groups should be helping to solve social problems, Mr Craig believes.
And he wants God acknowledged in City Hall, "not a strange god we do not know".
MATT O'CONNOR - English Democrats
Known as the founder of the controversial campaign group Fathers 4 Justice, Matt O'Connor was approached by the English Democrats to represent them in the mayoral election.
His party intends to address a perceived imbalance in the way people in England are treated compared with the rest of the UK, on issues such as funding and Parliamentary voting.
Mr O'Connor was born in Manchester in 1967 and made his name fighting for fathers' rights after having problems of his own in maintaining contact with his children.
He has also been a member of the Fabian Society, CND and Amnesty International.
WINSTON McKENZIE - Independent
Winston McKenzie says many people believe it is "impossible" there will ever be a black mayor of London, but he is aiming to ensure history is "rewritten".
Boxing runs in the 51-year-old's family - he was an amateur who represented England, while his brother Duke was also a champion.
Having worked with under-achieving children as an educational motivator, he is now standing as the only independent candidate in this year's race.
He would dramatically scale back London's congestion charge, both in terms of geography and its hours of operation, and promises to take a "ruthless" approach to gun and knife crime.