The exact time people will receive a “warning of disaster” on their phones later this month has been revealed.

The UK wide test of the life-saving public Emergency Alerts system will take place at 3pm on Sunday, April 23.

The system has already been tested on a local level in East Suffolk and Reading, with people receiving an alert on the home screen of their mobile phone, along with a sound and vibration for up to ten seconds.

During this test, the public does not need to take any action, and the sound and vibration will stop automatically after ten seconds.

All people will need to do is swipe away the message or click ‘OK’ on the alert to clear their home screen.

The alert will work just like a ‘low battery’ warning or notification, and the mobile phone will continue to work as normal.

Chancellor of the Duchy of Lancaster, Oliver Dowden MP said: “Put the date in your diaries - at 3pm on 23 April, we'll be testing our new national Emergency Alerts system.

“Getting this system operational with the national test means we have another tool in our toolkit to keep the public safe in life-threatening emergencies. It could be the sound that saves your life.”

Chair of The National Fire Chiefs Council, Mark Hardingham, added: “We must use every tool at our disposal to keep people safe, and we need everyone to play their part - and the new Emergency Alerts system is one way we can do this.

“For 10 seconds, the national test may be inconvenient for some, but please forgive us for the intrusion, because the next time you hear it - your life, and the life-saving actions of our emergency services, could depend on it.”

Similar systems are already in place in countries such as the US, Canada, Netherland and Japan, where best practice has shown that they work more effectively in a real emergency if people have previously received a test.

The system will be used very rarely - only being sent where there is an immediate risk to people’s lives - so people may not receive an alert for months or years.

In the UK, alerts could be used to tell residents of villages being encroached by wildfires, or of severe flooding.

National Police Chiefs’ Council Lead for Civil Contingencies, Assistant Chief Constable Owen Weatherill said: “Warning and informing the public at speed during times of crises can be vital. We look forward to further developing the use of the Emergency Alerts capability and how it can have real benefits for the public to protect and preserve life, as well as supporting policing’s wider response to critical incidents with partner agencies.

“Alongside partners, we will continue to listen carefully to public feedback and ensure the use of Emergency Alerts has a positive impact.”