Boos for 'union barons' and bendy busesas Boris launches his election campaign

Boris Johnson launches his official campaign in Richmond (Susannah Ireland)

"Welcome to Richmond," said Zac Goldsmith, hosting Boris Johnson's campaign launch in his south-west London constituency. "Where the sun always shines," he added.

Certainly, Mr Johnson had no reason to fear a frosty reception. The well-heeled outer London borough is home to natural supporters of Mr Johnson's low-tax, car-friendly, union-busting mayoralty. Addressing a packed hall from the lectern in Duke Street Church, Mr Johnson was in his element. Supporters kitted out in blue and white "Back Boris" T-shirts roared obligingly at every campaign promise and crime reduction statistic, with pantomime boos reserved for Labour's repeat candidate Ken Livingstone and the "union barons".

With three weeks to go until the 4 May vote, the Mayor has a 53 to 47 per cent lead over his main rival. "Do you want a City Hall of full of car-hating, outer London-ignoring, bendy-bus-fetishist Trotskyites?" asked Boris. "No!" cried the faithful.

The biggest cheer was for the new generation of double-decker Routemaster buses that Mr Johnson introduced. "Do you want German-designed, 18-metre long bendy buses blocking our streets like beached whales?" Believe it or not, they didn't.

Surrounded by a phalanx of minders and PR people, the Mayor went for a lunch-time meet and greet. "He is just so charming," said Isabel Booth, 18, who began the day a Ken supporter but is now voting for Mr Johnson.