BE ready for a nationwide test of the public Emergency Alerts system this Sunday.

Everyone with a 4G or 5G mobile phone will receive a message on their home screens, along with a sound and vibration for up to 10 seconds.

The message will read: “This is a test of Emergency Alerts, a new UK government service that will warn you if there’s a life-threatening emergency nearby.

“In a real emergency, follow the instructions in the alert to keep yourself and others safe.

“Visit gov.uk/alerts for more information.

“This is a test. You do not need to take any action.”

The test of the system, which will be at 3pm on Sunday 23 April, follows successful pilots in East Suffolk and Reading.

When you receive the message, which will be like a “low battery” warning, you should swipe away the message or click “OK” and continue to use the phone as normal.

You do not need to take any other action.

The test will activate five hours into the London Marathon and an hour after kick-off in Bournemouth’s home tie against West Ham, as well as during some St George's Day parades attended by local Scout groups.

A statement from the Government said Emergency Alerts have been used successfully in a number of countries, including the US, Canada, the Netherlands and Japan, where it has been widely credited with saving lives during severe weather events. 

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

It added that Emergency Alerts will allow urgent messages to be sent quickly to nearly 90%of mobile phones in a defined area when there is a risk to life, and provide clear instructions about how best to respond.

“Emergency Alerts in other countries have been shown to work more effectively in a real emergency if people have previously received a test, so they know what an alert looks and sounds like.

“The system will be used very rarely and only where there is an immediate risk to people's lives, so people may not receive an alert for months or years.”

Mark Hardingham, Chair of the National Fire Chiefs Council, said: “We must use every tool at our disposal to keep people safe, and we need everyone to play their part.

“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.”