Up to 4.5million people will be advised to stay at home as part of a new shielding plan, according to reports. 

A new risk model will look at an individuals' health, weight, age and sex before determining who is most "at risk" of contracting coronavirus, according to The Sunday Telegraph.

It is understood this measure will be introduced initially in areas with high rates of infection but sources told the newspaper it could be rolled out "on a blanket basis" if the overall infection rate across the country becomes a concern. 

It is unclear however whether this is enforceable or merely advisory and what impact it will have on those with work commitments. 

The letter, published by the newspaper and written by Stuart Miller, director of adult social care delivery at the Department of Health and Social Care, reads: "You will know already that we are experiencing a rise in confirmed Covid-19 cases, across the UK population.

"I need to alert you to the first signs this rise is being reflected in care homes too.

"Over the past three days, Public Health England (PHE) has reported an increase in notifications of Covid-19 cases in care homes.

"Testing data has also shown an increase in the number of positive results.

"Currently, the infections are mainly affecting the workforce but clearly there is a risk the virus will spread to care home residents, or to other parts of the care sector.

"Unfortunately, in some care homes with recent outbreaks, this does appear to have occurred, with residents also becoming infected."

This news comes as the R rate nationally rose to between one and 1.5 on Friday, the highest levels since March.

Yesterday, a further 3,497 cases of coronavirus were recorded, the sharpest increase on a Saturday in four months.

Meanwhile nine more people died of coronavirus, bringing the death toll in Britain to 41,623.