The document, seen by the Guardian, is the first time health chiefs tackling the virus have admitted that they expect it to circulate for 12 more months and lead to huge extra strain on an already overstretched NHS.

It also suggests that health chiefs are braced for as many as 80% of Britons becoming infected with the coronavirus over that time.

Prof Chris Whitty, the government’s chief medical adviser, has previously described that figure as the worst-case scenario and suggested that the real number would turn out to be less than that. However, the briefing makes clear that four in five of the population “are expected” to contract the virus.

The document says that: “As many as 80% of the population are expected to be infected with Covid-19 in the next 12 months, and up to 15% (7.9 million people) may require hospitalisation.”