Windscreen stickers which show a vehicle's emissions levels have become a legal requirement in several key French cities including Paris.
British drivers heading to the French capital are advised by the RAC that driving without a French 'clean air' sticker - which costs as little as £3.20 - makes them culpable for an on-the-spot fine of up to £117.
Drivers of non-French-registered vehicles though, have been offered a degree of leniency - given until March 31 to fully comply with the Crit'Air initiative. An English language section of the government website responsible for stickers launches on February 1.
The scheme in Paris began on January 15, while those in Lyon and Grenoble have been running since the start of the year.