Emergency alerts: How to switch off phone siren set to cause chaos in just weeks

But there are fears a lack of knowledge about the alert will lead to an increase in crashes on motorways, and could even cause harm to domestic violence victims if it alerts an abusive partner to a secret phone hidden in the property.

The alerts are automatically enabled, meaning that everyone will receive the urgent message unless they deliberately turn it off.

To opt-out of the service, simply go to your phones settings.

On iOS, enter the "Notifications" tab.

It will then be possible to switch off "severe alerts" and "extreme alerts".

Britons with an android phone should search "emergency alert" in their phone's setting section.

They will then be able to use the toggles to switch off the alerts.

The emergency siren will not be received if a phone is in airplane mode.

Older smart phones which cannot access the 4G or 5G phone networks will also not get the message notification.

While the alerts are easy to turn off, Government ministers have explained that Britons will benefit from the new system.

Chancellor of the duchy of Lancaster, Oliver Dowden MP, said last month: "We are strengthening our national resilience with a new emergency alerts system, to deal with a wide range of threats – from flooding to wildfires.

"It will revolutionise our ability to warn and inform people who are in immediate danger, and help us keep people safe.

"As we’ve seen in the US and elsewhere, the buzz of a phone can save a life."