A second national lockdown is a possibility and stringent measures are needed to avoid it at all costs, a leading expert has warned.

Professor Peter Horby, of the University of Oxford, told the BBC’s The Andrew Marr Show on Sunday that the country was in a “precarious position” with rising coronavirus case numbers, hospital admissions and deaths.

Prof Horby, who is also chairman of the Government advisory group for new and emerging respiratory virus threats advisory group (Nervtag), said that hospitals in parts of northern England were already starting to come under pressure.

He said that stringent measures were needed to halt the spread of the virus and added: “We are already seeing in some parts of the North that some hospitals are starting to see the pressure.

“We have a doubling time of about eight to 15 days so it is not long before those ICU (intensive care unit) beds could be full and we could be in a really difficult situation.

“So I am afraid we are going to have to make some very difficult choices and act very quickly.”

When asked if the country faced a second national lockdown, he said: “I think that’s a possibility and we have to do what we can to avoid that at all costs.”

His comments come as the Prime Minister is set to detail a new three-tier system of restrictions with measures expected to force pubs and restaurants to shut across the North of England and see millions of people banned from mixing indoors and outdoors When asked why case numbers were much higher in the North, Prof Horby said they had not been as low as the rest of the country and people were having more contact with others.