The introduction of a controversial French law that requires almost all motorists to carry a breathalyser kit has been postponed until March next year, according to the Institute of Advanced Motorists (IAM).

The country's police force has been making drivers - particularly British ones - aware of the impending change since the summer, with the law due to be brought into force on November 1.

However, the change has been put back to March 1 and fines for those caught without breathalyser kits will not be issued until after that date, although bizarrely moped riders will continue to be exempt from the 11 euro fine. Single- and double-unit kits both meet legal requirements and are available now for less than £2.

The French authorities are trying to reduce the number of alcohol-related accidents in the country, and with their limit set considerably lower than the UK equivalent - 50mg per 100ml of blood versus 80mg in Britain - it's easier to be over the limit.

IAM director of policy and research Neil Greig said: "The new French rule is a genuine attempt to reduce the number of alcohol-related accidents. France's lower limit means it's very easy to be over the limit the morning after as well. As always, the best advice for road users is not to drink and drive at all."

Motorists enjoying French roads are already required to carry high-visibility vests and warning triangles for use in an emergency. Cars and motorbikes from Britain also need to display a `GB' sticker or GB-badged number plate.