The fascist British National Party could win a seat in the London Assembly, claims incumbent Mayor of London and Labour candidate Ken Livingstone.

Londoners will go to the polls to choose the 25-member Assembly and elect the Mayor.

Mr Livingstone said that London’s future as a united diverse city” was at risk if the BNP get a seat. The party already has 11 councillors on Barking and Dagenham council and more than 50 worldwide.

Mr Livingstone was campaigning in Holloway today with Doreen Lawrence, mother of murdered black teenager Stephen.

She has been critical of the candidacy of the Tory candidate Boris Johnson.

The BNP needs five per cent of the vote to gain representation on the Assembly.

“The true character of the BNP is extreme right wing politics,” said Mr Livingstone.

“Like all fascist parties the BNP seek power with populist policies but their aim is to divide communities and foster hatred and violence.

“We have to get across one simple fact: there’s only one way to stop the BNP, which is by actually going out to vote against them. A low voter turnout will help the BNP get elected.”

Last week the fascist party urged its supporters to cast their second preference votes for the Tory candidate to ensure that Mr Livingstone was removed from office.

Boris Johnson responded: “I utterly and unreservedly condemn the BNP and have no desire whatsoever to receive a single second preference vote from a BNP supporter.”

Mr Johnson, who is leading incumbent Mayor and Labour candidate Ken Livingstone in opinion polls, has been criticised by prominent black Londoners over comments he made as a journalist.

References to “smiling piccaninnies” in some of his columns have been used as evidence of his unfitness to lead multicultural London.

The BNP candidate for Mayor of London, Richard Barnbrook, was ridiculed in 2006 when the Evening Standard newspaper publicised a copy of a film produced and directed by him described as “Marxist gay cinema.”

Mr Barnbrook is the London co-ordinator of the BNP, which has promised to remove homosexuality from society, deeming it “wrong and unhealthy for any community.”

Yesterday Mr Johnson attacked Mr Livingstone for, among other things, “failing to stand up against controversial figures preaching hate.

“He invited Muslim Cleric Yusuf Al-Qaradawi to London, a man who supports the death penalty for homosexuals.”

He also produced a document called Ken’s Broken Promises.

“His record shows he is unsuitable for another four more years in office. He is tired, stale and out of touch,” said the Tory candidate.

“It is time for a change and a fresh approach for London. My policies on crime, transport and housing offers the change that London deserves. A change that is so badly needed.”

Mr Johnson claims that as Mayor, Mr Livingstone has not kept his election promise over housing targets, a 2004 manifesto promise to bring late night tube trains on Fridays and Saturdays and “failed to promote a tolerant and cosmopolitan London by making anti-Semitic remarks more than once – firstly towards the Ruben Brothers and secondly to an Evening Standard journalist. The court case that followed cost the taxpayer £200,000.”

The Lib Dem candidate yesterday launched a “Contract with London” promising a 5% cut in crime every year, a comprehensive plan to get London moving “within 3 months,” and urgent action to turn London’s 83,580 empty properties into sustainable homes.

Brian Paddick also pledges to “make London the greenest capital in Europe,” and hold regular public meetings and “end the cronyism” by making the Mayor’s cabinet directly elected by London Assembly members.

“Ken Livingstone has failed to deliver on his promises, Boris Johnson has failed to deliver anything while I have a proven track record of delivery,” he said.

Today the Paddick campaign announced the launch of a new website.