Britain plans to test a new emergency alert system on Sunday, so that at 3:00 pm local time (1400 GMT) millions of mobile phones will sound like a siren in addition to vibrating.

The national system, modeled on similar systems in Canada, Japan, the Netherlands and the United States, aims to warn the public if there is a life-threatening danger nearby, but has raised suspicions of privacy violations by the "custodial country".

A message will appear on the mobile phone saying: "This is a test for Emergency Alerts, a new British government service to warn you if there is a life-threatening emergency nearby."

Emergency agencies and the government hope to use the system to alert people during disasters such as severe floods and fires.

The 10-second alert, even if the phone is on silent, is expected to disrupt technical and sporting events, including English Premier League football matches.

The World Snooker Championship organizers will stop playing just before the alert, while the London Theater Association has advised its members to tell the public to turn off their phones.

Drivers have been warned not to pick up their phones during the test, and people who don't want to receive alerts can cancel the service in their device settings.

Deputy Prime Minister Oliver Dowden said: "Keep calm and carry on. That's the British way and that's exactly what the public will do when they receive this alert test at 3pm today."

"The government's first job is to keep people safe, and this is just another tool in the emergency toolkit," he added.

But some conservative figures have criticized the test, with former minister Jacob Rees-Mogg urging people to defy government calls and turn off phones, saying "we are back in the incubator state".

Sarah Vine, a Daily Mail columnist and ex-wife of government minister Michael Gove, described the idea as "as terrifying as it is tiring".

"Terrifying because it is a reminder of the tyranny imposed on us all by technology that has invaded our homes," she wrote.

Dowden sought to reduce concerns about privacy and intrusion, stressing that "all people have to do is remove the message or click OK."

"The test is safe, free to receive, and one-sided and does not reveal anyone's location or collect personal data," he added.

But Judy Edworthy, an expert in alarm systems and professor of psychology at Plymouth University, considered the alert system a positive development, even if its first test surprised people.

"If (the regime) encourages people to look at their phones, read the message and act accordingly, it can be said that it has succeeded," she said.

Lawmakers also criticized the awarding of the alert system contract to Japan's Fujitsu, which is responsible for flawed postal service systems that have led to fraud convictions of managers.