The UK could face close to a year of social distancing measures to safeguard the NHS’s ability to cope with coronavirus, according to newly published scientific advice to ministers.

Documents made public today show scientists agreed on Monday that the only realistic prospect of controlling the virus and preventing intensive care wards being overwhelmed would be to start an alternating policy of more and less strict rules on social distancing.

Yesterday the prime minister Boris Johnson said the UK could “turn the tide of this disease” within 12 weeks and send the virus packing.

But according to a consensus statement agreed by the Scientific Pandemic Influenza Group on Modelling, the restrictions will have to last much longer.

It is a panel of experts convened by the Department of Health and Social Care to advise on the UK’s response to a pandemic based on infectious disease modelling and epidemiology.

The document is likely to pose serious questions for the government about its policy and whether the UK is doing enough.

It said: “It was agreed that a policy of alternating between periods of more and less strict social distancing measures could plausibly be effective at keeping the number of critical care cases within capacity.

“These would need to be in place for at least most of a year. Under such as policy, at least half of the year would be spent under the stricter social distancing measures.”

It added that the triggers to restart measures after they were relaxed could be set at a national and regional level, suggesting areas like London could face different restrictions to other parts of the country.

It said: “There would be a two to three week delay between measures being put into place and their impact being felt in [intensive care units].”

The document reflects advice to the government, not what ministers have decided they will do.

The statement said that scientists accepted isolating cases, households and social distancing of vulnerable people would not be enough to stop the NHS being overrun with critically ill patients.

They added: “It was agreed that it is unclear whether or not the addition of general social distancing measures to case isolation, household isolation and social distancing of vulnerable groups would curtail the epidemic.