Â鶹´«Ã½Ó³»­

The Cour de Cassation ruling means an existing but often ignored margin of error of 0.03mg/l of breath must always be taken into account.

The current drink-drive limit in France is a maximum of 0.5g of alcohol per litre of blood (0.8g in the UK) and corresponds to 0.25mg per litre of breath (0.35mg/l in the UK). From 0.25mg/l, drivers risk having their licence suspended and a €135 fine.

When over 0.40mg/l, the driver has to go to court and can face a €4,500 fine and two years in prison.

The error margin means drivers could avoid that larger fine if their test registered 0.43mg/l.

The change comes as the number of road accidents is increasing. In February, there was a rise of 22%, partly said to be linked to the destruction of speed cameras.