All new electric vehicles must be fitted with a noise-emitting device to alert other road users to their presence.

The European Union rule comes into force tomorrow, following concern that vehicles without a petrol or diesel engine are too quiet, putting pedestrians, cyclists and other vulnerable road users at risk because they do not realise they are approaching.

New types of quiet electric and hybrid vehicles with four wheels must now be fitted with an acoustic vehicle alert system (AVAS) which will generate a sound similar to that made by a conventional engine.

The AVAS must be activated when a vehicle is reversing or travelling below 12mph, but the driver will have the power to deactivate it if judged necessary.