London's seven mayoral candidates

There are seven candidates competing to be mayor of London on 3 May. Here is a guide to them, in alphabetical order.

SIOBHAN BENITA, Independent

Former civil servant Siobhan Benita is the only independent candidate standing in this year's London mayoral race.

She has high-profile backers, including former Cabinet Secretary Sir Gus O'Donnell and actor Tom Conti.

The Times newspaper has named her "the one to watch", while the Evening Standard has dubbed her the Borgen candidate, after the Danish television series in which a female outsider takes victory in the general election.

Policy-wise, she is the only candidate backing a third runway at Heathrow airport, and wants to make the Tube run later on Friday and Saturday nights.

But she argues she has been shut out by the media and hasn't been given the air time to put her case.

CARLOS CORTIGLIA, BNP

The British National Party confounded expectations by fielding a Uruguayan national, Carlos Cortiglia, as its candidate for London mayor.

Mr Cortiglia moved to the UK in 1989 and has lived and worked in London ever since.

He says he is "astonished" by the "hostility shown by many of the migrants towards the British and their way of life".

Mr Cortiglia says he wants "a British Britain" - and a requirement for anyone coming to live in this country to speak English.

The former BNP press officer has also mooted the abolition of the London congestion charge, the promotion of renewable energy sources like solar power, and made plain his opposition to the use of water cannon on the capital's streets.

BORIS JOHNSON, Conservative

Before Boris Johnson was elected as London Mayor in 2008 the former MP had already become one of Britain's most recognisable political figures with his colourful - and sometimes gaffe-prone - work as a journalist and TV panel show guest.

As mayor he has at times appeared critical of coalition government policy and is often described as a rival to Prime Minister David Cameron.

He has introduced a number of changes to public transport in the capital, banning alcohol consumption on buses and tubes, launching a bicycle hire scheme known as "Boris bikes", and investing millions in the development of a new "routemaster" after ditching the "bendy bus".

If re-elected, he says he will cut waste at City Hall and invest in transport infrastructure.

JENNY JONES, Green Party

The Greens' candidate Jenny Jones is a long-standing member of the London Assembly and former archaeologist who wants radical reductions in both inequality and carbon emissions.

She spent 10 years studying carbonised plant remains in the Middle-East, to learn about how social changes affected peoples' diets, before entering politics.

Her CV also boasts experience as a financial controller, four years as a Southwark councillor, and a stint as London's deputy mayor, under Ken Livingstone.

She has vowed to increase the congestion charge and eventually replace it with a pay-as-you-drive charging scheme, and impose a 20mph speed limit across much of the capital if elected.

But she insists her manifesto goes beyond what might be seen as classic Green issues - with pledges on business, jobs and housing.

KEN LIVINGSTONE, Labour

London's first elected mayor, Ken Livingstone has a reputation as an outspoken, independent and often combative figure, whose flagship mayoral policy was the introduction of the congestion charge.

Mr Livingstone was re-elected in 2004 - but lost out in his battle for a third term to Boris Johnson in 2008.

During his spell as mayor he unsuccessfully fought the Labour government as it introduced an ill-fated public-private partnership plan for the London underground network.

A fierce opponent of Margaret Thatcher in the 1980s and a frequent rebel within his own party, Mr Livingstone was accused by critics of belonging to the "loony left".

His manifesto includes pledges to cut fares on public transport and boost affordable-home building in London.

BRIAN PADDICK, Liberal Democrats

Policeman turned politician Brian Paddick served over three decades for the Metropolitan police before resigning in 2008 to stand as the Liberal Democrat mayoral candidate.

Unlike his opponents from Labour and the Conservative parties he has not served in political office. However he did rise to become the Deputy Assistant Commissioner of the Metropolitan Police before standing down.

Famous for a "softly softly" approach to policing in Brixton he pursued prosecutions for use of other illegal drugs but not cannabis.

It was a policy which earned him the nickname "cannabis cop".

If elected Mayor, he plans to put more police on the streets in communities most at risk from gun and knife crime and ensure that all London's buses, taxis and most commercial vans run on electricity by 2020.

LAWRENCE WEBB, UK Independence Party

Blocking EU regulation of London's bankers and curtailing the extension of the low-emission zone are two of Ukip mayoral candidate Lawrence Webb's main political priorities.

Mr Webb was once the chairman of his party in London, which he hails as "one of the world's greatest global financial capitals".

But small businesses are also a central concern for the candidate, who worries that new rules on cutting vehicle emissions will force ice-cream vans "off the streets of London".

A former nightclub promoter, Mr Webb believes VAT on beer should be slashed from 20% to 5%.