Over half a million Brits could be killed in a coronavirus pandemic, a secret government report has warned.

Ministers are braced for 50million people to catch the killer Covid-19 bug – meaning that 80% of the population could be infected.

A memo seen by The Sun says the “reasonable worst-case” would involve infection rates snowballing for three months before killing over 500,000.

The figures are included in a “sensitive” government report called “Covid-19 Reasonable Worst Case Scenario”.

The virus would mostly be expected to kill OAPs and those with pre-existing illnesses.

The virus could claim millions of lives worldwide

It comes as the World Health Organisation warn the killer infection could turn into a pandemic – with more than 80,000 confirmed cases worldwide.

The death toll is fast approaching the 3,000 total.

England’s top doctor Professor Chris Whitty said yesterday: “There’s no secret there’s a variety of things you need to look at, like school closures.

People around the world have started wearing face masks as the virus spreads

“We might want to look at things like should people stay at home with their families in that situation.

“It’s one of the things we would want to think about.”

Earlier this week several schools closed their doors after pupils returned from trips to coronavirus-hit Italy.

The virus has affected an estimated 80,000 people

229 people in Italy have tested positive for the virus, seven have died, police have manned checkpoints around a dozen quarantined northern towns.

Schools were closed, theatre performances cancelled, and Venice Carnival celebrations were called off, while producers said filming on the latest Mission: Impossible movie starring Tom Cruise has been halted.

Health minister Matt Hancock said the Government was not aware of any Britons who were in the quarantined areas of northern Italy, but he urged anyone there to make contact with the embassy in Rome.

He added: "But we are clear that, if you come back from northern Italy and you have symptoms, then you should self-isolate."