Firms transporting goods into the capital face £200 a day charges if they fail to ensure their lorries meet strict emissions standards following the launch today of the new London-wide Low Emissions Zone (LEZ).

Under the new scheme, all lorries over 12 tonnes entering the 610 square mile zone will have to meet strict EU standards governing nitrogen oxide and particulate emissions or face the daily charges. Failure to pay the charges will result in £1,000 fines.

The £49m scheme will use cameras to check lorries against a database of vehicles that comply with the standards.

Transport for London (TFL), which is in charge of the scheme, said that the charges and fines had been set purposefully high to "encourage operators to clean up their fleets rather than to encourage regular payment of the charge".

It added that the scheme will be expanded from July this year to include all diesel engined vehicles weighing over 3.5 tonnes, including buses and coaches. Further extensions to the scheme are planned for October 2010 when smaller diesel vans weighing over 1.205 tonnes will have to comply with the standards to avoid the daily charge.

TfL said that it would now give transport firms a 28-day warning period to comply with the new standards before imposing the charges. But Kate Gibbs, a spokeswoman for the Road Haulage Association (RHA) said that the grace period may have to be extended. "There are around 20,000 heavy goods vehicles in the London area and a percentage of them need to fit filters to comply with the rules," she explained. "This has created a supply shortage of the necessary parts and while we welcome the 28 day grace period we have to hope TfL will be suitabl;y sympathetic if some firms are still not in a position to comply in a month's time."

The RHA has consistently criticised the plan, claiming it represents a costly means of tackling a problem that will disappear over the next two years as hauliers replace older vehicles with new cleaner lorries. "All new lorries exceed the standards," said Gibbs. "So this is a very expensive way of solving a problem that is fast disappearing."

However, London Mayor Ken Livingstone insisted the new rules would have a sizable impact on the city's air quality. "Thousands of Londoners suffer ill-health from pollution released by traffic fumes," he said. "The zone, along with measures I am taking to clean up taxis and buses, and supported by European standards for new vehicles, will mean that by 2012 the number of Londoners that live in areas that register levels of air pollution that are dangerous to health will be reduced from 1.3 million to 400,000 for oxides of nitrogen, and from 500,000 to just 70,000 for the most dangerous pollutant, fine particles."