Mr Johnson cites research which was suppressed by the Mr Livingstone which shows that it is safer for cyclists and motorbikers to use the bus lanes together. The present situation is that should a motorbike enter the bus lane they could face a £120 penalty if caught.

Transport for London was given the go ahead by the Mayor in 2002 to run trials in two areas allowing motorbikes and scooters can use bus lanes. The three-year study reveals that the number of accidents almost halved. Mr Johnson will pledge to publish the suppressed TFL research in full. He is believed to have said: "Ken Livingstone has refused to release the report, and leaked emails show his office has actively tried to interfere with the findings.

"Not only is this a fraud on Londoners with motorcycles but it is a cynical refusal in an election year to implement a measure that could both cut congestion and save lives." It could be said that Mr Livingstone is shying away from this issue as has claimed credit for the huge rise in cycling and has unveiled plans to create 12 cycle "super-highways" and introduce free bikes for hire. Many people have made the switch to motorbikes since 2003 in order to escape the dreaded congestion charge.