Ken: fatal flaw in Johnson plan to bring back Routemasters

In an ITV London debate, the Mayor warned that his rival's plans would never get off the drawing board because no manufacturer would want to be sued over deaths or injuries caused by the open-backed buses.

But Mr Johnson hit back, countering that his new design would be safer than the bendy buses they would replace. He also declared that he wanted all bus crime to be wiped out - a "100 per cent reduction" - during his first four-year term at City Hall.

The debate, to be screened on ITV1 tonight, saw Mr Livingstone, Mr Johnson and Liberal Democrat Brian Paddick clash repeatedly in their rowdiest televised hustings to date.

With just over a week to go before polling day, all three candidates were heckled and jeered as they sought to score points against each other on everything from transport to crime, to their fitness for office.

The Mayor used the debate to unleash a fresh attack on Mr Johnson's £100 million plans to phase out bendy buses and replace them with a new generation of disabled-friendly Routemasters.

He said: "No one will design one because people would be liable to be sued by the relatives of people who fell off the back and died.

"You used to have double figures every year for people falling off the buses." Mr Livingstone later said that he was referring to figures from the early Nineties, when Routemasters were last in use on a major scale.

He said that in the Seventies, when the bus made up half the fleet, around 20 people a year died in accidents, caused mainly when people tried to hop on the back of a bus, missed and were then run over.

Mr Johnson dismissed the claims, declaring "bendy buses are twice as dangerous as any other bus". He pointed to figures showing that there have been twice as many pedestrian and cyclists injuries involving the articulated buses as normal buses.

Today Mr Livingstone continued the attack by criticising Mr Johnson's lack of proposals for the Tube. The Mayor said it gave Londoners a "crystal clear choice" on which candidate was better suited to run the capital's transport network.

On a visit to a central London Tube station, he compared his record with that of his Tory rival. "I have put forward a clear programme and management for the Tube in this election, whereas Boris Johnson has produced complete incoherence on a £1 billion a year programme for a system on which three million Londoners travel every day," he said.

London's Mayor - You Decide, will be broadcast on ITV London at 10.35pm