BORIS Johnson wants drivers to do their bit before the Olympics and switch off their engines when parked, loading or waiting at the roadside.

The no-idling campaign is part of a Transport for London drive to improve air quality, cut pollution and clean up the city ahead of the games.

It comes after research commissioned by the London mayor’s office suggests poor air quality plays a part in 4,300 premature deaths in the capital each year.

Mayor Johnson said: “I am committed to improving Londoners' quality of life by bringing the best of village living into the city.

“This includes delivering cleaner, healthier air.

“Turning off engines when stationary for more than a minute creates a host of positive benefits by reducing pollution and using less petrol to save people money.

“This small individual step can collectively make a massive difference and help improve our great city.”