A plan to test a mobile phone emergency siren could bring chaos to the roads with drivers panicking upon hearing a loud piercing alert, ministers have been warned.

The loud, 10-second blast will be sent to all mobiles on Sunday, April 23 as part of a nationwide test of the system announced last month by Oliver Dowden, the Cabinet Office minister, reports the Daily Telegraph.

However, officials are concerned that the potential consequences have not been fully thought through. Discussions have taken place with the transport sector, domestic violence charities and sporting officials as well as the police, fire and ambulance services about the trial, said the newspapers report.

Officials have met with the RAC to discuss how any risk to drivers can be reduced to avoid car crashes.  

Road safety campaigners have warned that the siren could distract drivers caught unawares.

Edmund King, president of the AA, welcomed the scheme, but questioned how wise it was to test it on a day “Sunday drivers” – often less experienced motorists – take to the roads.

“If they have the phone in the car and an odd sound goes off there could be some form of panic,” he said.

“Even if they have a hands-free system the odd sound could mean they reach for the phone. So, there’s no doubt that there’s a threat of distraction for some drivers.”

Motorway signs will also be used in the run-up to the test to warn drivers not to check or use their phones.  

Ministers have also approved a major publicity campaign to advise the public about the siren.

It is understood ministers believe the “minimal” risk to the public by testing the system is outweighed by the benefits of having a scheme that can warn of emergencies such as floods, wildfires and terror attacks. Similar systems are used in other European countries and the United States.

.