BORIS Johnson has warned the NHS could be "overwhelmed" if people do not act to now to stop the accelerating spread of coronavirus, as he urges residents not to visit loved ones on Mother's Day.

The PM called on the public to join a "heroic and collective national effort" and follow social distancing advice and stay-at-home advice.

The number of people who have died in the UK with coronavirus rose to 233 on Saturday, as cases topped 5,000. 

It comes as NHS England has said it plans to write to 1.5 million people most at risk.

Those at-risk people will receive letters or text messages strongly advising them not to go out for 12 weeks to protect themselves, the government said.

They include people who have received organ transplants, are living with severe respiratory conditions such as cystic fibrosis or specific cancers, such as blood or bone marrow.

In a message to the country on Saturday evening, Mr Johnson said: "The numbers are very stark, and they are accelerating.

"The Italians have a superb health care system. And yet their doctors and nurses have been completely overwhelmed by the demand.

"The Italian death toll is already in the thousands and climbing. Unless we act together, unless we make the heroic and collective national effort to slow the spread - then it is all too likely that our own NHS will be similarly overwhelmed."

He said the UK is only "two or three" weeks behind Italy, adding that he recognised the government was imposing measures "never seen before either in peace or war" - but said they were essential.