Drink drivers in France will be able to avoid a ban if they install breathalyser 'alcolocks' that prevent their vehicles from starting if they are over the alcohol limit.

They will have to blow into the breathalyser before the engine will start. They will then be required to blow a second time — set randomly at between five and 30 minutes later — to check that they are still under the limit, with the aim of preventing someone else starting the car for them.

The government approved the measure this week after a year-long trial of the scheme in seven French departments.

Drink drivers lose six of 12 points on their license for a first offence. They only receive a six-month suspension of their licence if they lose the remaining six points.

The authorities will now be empowered to order drink drivers with a blood alcohol level between 0.8 and 1.8 g/l to install ‘alcolock’ breathalysers at their own expense as an alternative to a ban.

First offenders may also be required to install the devices, which cost more than £1,100 to buy and install, or £85 a month to rent.

They would have to keep the breathalysers for six months, but courts may extend that to a maximum of five years. Drink drivers may also be fined up to £3,850.