And they could be fined up to £118 if their vehicle does not display an official vignette (sticker) showing what its NOx (nitrogen oxides) emission levels are.
The French government has introduced the Crit'Air scheme in Paris, Lyon and Grenoble covering six vehicle pollution categories – from the cleanest (electric and hydrogen vehicles) to the dirtiest (pre-2001 diesels).
Nearly 3.2 million UK holidaymakers take their cars across the Channel each year and many will be unaware that ALL private vehicles, both domestic and foreign and also hired cars, must display an official Crit'Air sticker on their windscreen for travel in Paris, Lyon and Grenoble.
Be careful if you drive in central Lyon, you'll need a special Crit'Air sticker
Failure to do so could mean a fine of up to €135 (around £118).
French officials will being carrying out spot checks on cars this summer and they will ban higher category cars from entering those cities on bad NOx pollution days.
Pre-2001 diesels were banned in Paris between 8am-8pm on all weekdays from July 1 regardless of prevailing NOx levels.
Good news for UK drivers is the Paris Peripherique ring road - used by many Brits on their journeys south - is outside the Crit'Air zone but anyone who strays off it into the city proper will need a sticker.
Going to Grenoble with your car? You must get a Crit'Air sticker
RAC European driving spokesman Rod Dennis said: "If you're planning a drive to France and there is even the smallest chance you might visit Paris, Lyon or Grenoble, make sure your car carries the relevant vignette. The process of having to apply for a sticker is far preferable to the embarrassment and inconvenience of being stopped and fined when you're in France.
"The RAC also understands further cities could roll the scheme out from the end of the summer – including Lille, Strasbourg, Bordeaux and Montpellier. It makes sense for UK drivers planning a trip abroad later this year to apply for a vignette now."
- Apply for a Crit'Air sticker well in advance of your journey to France at certificat-air.gouv.fr/en . They cost €4.80 including postage (around £4.20).