Owners of vans weighing between 1.2-tonnes unladen and 3.5-tonnes gross vehicle weight, which do not meet Euro3 emissions standards, will have to pay a £100 daily charge or be hit by a £500 fine for driving within Greater London.

With minibuses and specialist vehicles also becoming liable for the charge, which operates 24 hours a day, seven days a week, TfL estimates the new standard will affect 150,000 vehicles. Four out of five vehicles included in the LEZ for the first time are vans.

Most are already compliant, having been registered after 1 January 2002, but for those that are not manufacturers, having been pressured by London mayor Boris Johnson, are offering a range of scrappage, swappage and discounts on replacement vans.

Kulveer Ranger, the mayor’s environment director, claimed changes to the LEZ were crucial in delivering cleaner air and improving Londoners’ health.

“There is a range of options available to vehicle owners and the mayor has agreed deals with a number of vehicle manufacturers for discounts off new vehicles,” he said. “However, some options to make vehicles compliant, such as fitting an approved filter, can take up to three months to complete so I urge those who are affected to take action as soon as possible.”

The LEZ was originally scheduled to cover larger vans from 4 October 2010 but the move was deferred due to the tough economic climate to give the operators of the estimated 70,000 non-compliant vehicles more time to make the changes.