Mayoral aide 'wanted good news on road safety buried'

His alleged intervention came after a three-year study by Transport for London into whether motorcyclists should be allowed to use bus lanes. A trial had found that accidents on two routes where motorbikes were allowed into bus lanes were nearly halved.

But aide Kevin Austin allegedly ordered the rewrite to avoid the loss of the "green vote", because cycle groups opposed sharing bus lanes with motorcyclists.

Now the authors fear the new version will be a whitewash and conceal the road safety benefits shown by the trial, which took place in Brixton Road and Finchley Road.

It found the bus lanes were much safer for pedestrians, cyclists, car drivers and motorcyclists when motorcycles were allowed access, with a 42 per cent fall in the rate of collisions.

The report, presented to the Mayor in September, stated this, but officials claim they have been told to "bury" the findings and rewrite key sections to show the trial produced no safety gains.

City Hall insiders allege the order came amid fears that opening up bus lanes would alienate thousands of cyclists opposed to the move.

A source told the Standard: "We have been told to cook the books and expect the new report to be a whitewash. The original report showed that the trial sites were far safer than on other 'control' roads, including for cyclists.

"It meant the Mayor would have to open up bus lanes across London, followed by other regions closely watching the experiment. Now it has to be rewritten to appear the trial sites are no safer, so the Mayor can announce he will not proceed."

The study of the trial routes found accidents directly involving motorcycles fell by 45 per cent, compared with 19 per cent increase on a nearby 'control' route. Pedestrian casualties fell by 39 per cent against a three per cent rise on control routes. Collisions between cyclists and motorcyclists fell by 44 per cent.

The draft report said: "These figures demonstrate that crashes involving powered two-wheelers and other vulnerable road-users become more infrequent even when considering the increased concentration of riders."

Cycling campaign group CTC said "noisy" motorcycles travelling at higher speeds would intimidate cyclists, threatening the increase in commuters turning to bicycles.

But the draft report said: "The measure has no tangible adverse consequences to cyclists. In contrast to the level of concern... the number of casualties from collisions between cyclists and powered two-wheelers users is remarkably small."

A spokesman for the Mayor said: "There are serious issues of safety and efficiency involved in this issue so it required proper consideration based upon the collection and analysis of the relevant evidence.

"Transport for London had concerns about the validity of some of the early results of the study. These concerns were shared by GLA officials. TfL therefore undertook further work.

"All the results will be included in a final report, which will be submitted to TfL senior management and the Mayor. A decision will be made on the basis of full consideration of all of the evidence and this will be made public."