The Cabinet Office has said it will launch a review into the government emergency alert test after it didn’t go to plan yesterday afternoon.

The alarm was set to go off at 3pm as the biggest public communication exercise ever completed in the UK. The alert aims to warn the public if there is a danger to life nearby and appears as a notification on mobiles and tablets with advice on how to stay safe.

Despite the alarm being described as potentially ‘life-saving’ by Deputy Prime Minister Oliver Dowden, many phone users across the country reported that their alert came earlier than the predicted 3pm, whilst others got the alert more than 10 minutes after the time slot.

Those on the Three mobile network reportedly didn’t receive any alert at all.

A spokesperson for Three said: “We’re aware that a number of customers have not received the test alert. We’re working with the government to understand why and ensure it doesn’t happen when the system is in use.”

Since the alert was tested yesterday afternoon, some people have reported that they are now experiencing issues with making and receiving phone calls.

The Cabinet Office has said that engineers had not spotted a trend of mobile phones failing to work after the test, but were in the early stages of reviewing the results.

A UK Government spokesperson said: “We have effectively completed the test of the UK-wide Emergency Alerts system, the biggest public communications exercise of its kind ever done.

“We’re working with mobile network operators to review the outcome and any lessons learned.”

The problems come after the alert system had previously come under fire for the potential risks it could pose to those facing domestic abuse.

Many charities, including Women’s Aid, had warned the government that the alarm could alert abusers to secret second phones that women might be hiding. They advised women to switch off the notification in their phone settings to avoid the risk of it being found.

Women’s Aid shared video guidance on social media and said: “The emergency alerts sound will take place this Sunday at 3pm, even if your phone is on silent. If your phone is switched off it will sound when switched back on.”

To find out more about the government alerts visit the Gov website here.

To find advice or seek support on domestic abuse visit the Women’s Aid website here.