The measure has been introduced by the EU.
From tomorrow, all new electric cars are to be fitted with a device which gives off noise alerts.
There are concerns vehicles without petrol or diesel engines are too quiet – putting pedestrians, cyclists and other vulnerable road users at risk.
The ‘acoustic vehicle alert system’ will create a sound similar to a conventional engine when reversing or going below 12 miles per hour.
The EU, which introduced the rule, says the cars are most likely to be near pedestrians when they are backing up or driving slowly, although drivers will have the power to deactivate the devices.