The three leading candidates for the post of London mayor battle it out in the “Rainbow London Mayor Debate”. Watch Boris Johnson fighting hard to convince voters he can run the show at City Hall, Ken Livingstone campaigning on key issues like the buses, while Brian Paddick is trying to get a word in edgeways…not much difference to previously televised debates….except for the outfits!

** For full coverage of the mayoral election go to our special report **

Safer streets, better housing, more reliable transport….that’s what Ken Livingstone, Boris Johnson and Brian Paddick all want for London and it’s probably what most Londoners want for their city. But what’s the big difference then between “Red Ken”, “Crazy Boris” and …”Policeman turned Politician” Brian Paddick?

That’s still hard to fathom two weeks ahead of the May 1 London mayor election. But there was an air of tetchiness and getting personal during a Reuters Newsmaker debate at Reuters headquarters in London in front of an invited audience of around 250 people.

Liberal Democrat candidate Paddick told Livingstone he had “lost the plot” during his second term.

Ken “vote for me, I’m worth it” Livingstone hit out at Conservative candidate Johnson saying among the hardest decisions he ever had to take was to decide where to go for lunch with his former staff at “The Spectator” while he was editor of the right-wing magazine.

Johnson himself lashed out at the mayor for being inconsistent in his policies (”he wants millions of Chinese to come to London as tourists but is against a third runway at Heathrow” he said of Ken) and for “overpaying” his officials at City Hall. Ken himself was candid about what type of tourist he wants - the ones who spend the most money….not the Belgians…who according to him spend the least.

Under pressure from a lack of experience in managing large teams and projects, Johnson broke new ground (for himself) by finally announcing one person to join his ranks - Bob Diamond, the U.S.-born president of Barclays will join his team of advisors.

“I’m for taxpayer value” the Conservative candidate extolled, having collected the largest number of laughs for his customary one-liners…such as a commitment to keep funding the European Space Agency so he could send the (incumbent) mayor into orbit.

A business-like Livingstone weighed in with his eight-year track record as mayor, the safest pair of hands to run the capital’s 11.3 billion pound budget. Conscious of his audience of business professionals he stressed how he injected new life into the City of London, which apparently had been in decline when he took office.

“Slightly less regulation than our competitors” was his blueprint for future success of London as a financial centre.

Another one of Ken’s big themes for the next term, apart from the 2012 London Olympics, is the Crossrail, the much-delayed high-speed train linking east and west London, most importantly giving City workers quick access to Heathrow airport. There were a few gasps in the audience though when he prided himself on having improved London’s transport system…better than ever in his eyes but a source of frequent frustrations for most Londoners.

There was even a rare flicker of passion from earnest Paddick, when he was tackled by a member of the audience about his light-touch approach to drugs in south London when he was police chief - a policy, he said, he had pioneered in Brixton because that was what the “community” wanted and which had led to more arrests for drug dealing.

But as so often Paddick, struggling way off in third place in opinion polls, spent most of his time extolling his virtues as the man who will “listen and understand” and be “capable and competent”.

A straw poll on voting intentions among the audience saw Johnson, who is neck and neck with Livingston in real opinion polls, leading by a small margin. But, perhaps unsurprisingly, the majority didn’t raise their hands at all - still unsure on who should be leading London in the future?

Just in case you’re not sure….here’s a five-word primer for what they stand for …in the candidates’ own words at today’s Newsmaker:

- Paddick: listen, understand, act, capable and competent
- Johnson: change, democracy, safety, taxpayer value
- Livingstone (in 7 words): vote for me I’m worth it

** For full coverage of the mayoral election go to our special report **

*For all the latest Reuters news, analysis, pictures and blogs from the campaign trail, visit our special London elections site*

The battle for London Mayor has moved 250 miles north to Gateshead, where Tory contender Boris Johnson has been sticking his rhetorical boot into the Labour incumbent.

Johnson won laughs and applause from party activists at the Conservative Spring Conference as he eased his political stiletto between Ken Livingstone’s ribs.

He was merely repaying the compliment after Labour dedicated an afternoon to bashing Boris at their spring conference in Birmingham two weeks ago.

But while Labour Minister Hazel Blears called Johnson a “nasty, right-wing elitist, with odious views and criminal friends”, Boris opted for a more subtle approach.

“I know I am facing one of the wiliest and most redoubtable opponents in British politics … a man equipped as if by millennia of evolution with a prehensile tail with which to cling to office,” he told his appreciative audience.

“He has said some wise things. For instance, he said that only a ghastly dehumanised moron would get rid of the Routemaster bus, a point he then proved by getting rid of them himself.

“Just as the dinosaurs finally ceded dominion of the earth after their interminable epoch, so it is dawning on us that Ken Livingstone is visibly being transformed into “Ken Leaving-Soon” and the great Newtosaurus Rex has finally had its day.”

The mutual exchange of invective shows how the political temperature is rising ahead of the May 1 election, with the two contenders neck and neck in the polls.

The contest is already being seen as a proxy for the next general election - due by 2010 but potentially coming as soon as summer next year.

Johnson says it would be “momentous” if Labour loses the London Mayoral race.

You can see Johnson telling me why he is standing for Mayor here, and explaining why Boring Boris and Old Boris are two sides of the same coin here.

Boris Johnson talks to Tim Castle at the Conservative Spring Conference in Gateshead.

The Tory candidate for London Mayor says he will give it 100 percent should he become mayor and focus on making the capital safer because “it’s central to making a wonderful city yet more wonderful.”

Click on the video below.

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