Scientists advising government say plans for reintroducing stricter Covid measures “should be undertaken now” and be ready for “rapid deployment”.
Advising people to work from home could have the greatest impact on stopping viral spread, the Scientific Advisory Group for Emergencies (Sage) says.
It comes as ministers in England resist pressure to re-introduce controls, such as compulsory mask-wearing.
Covid hospital admissions and deaths across the UK are rising slowly.
Daily cases are now over 50,000, but the Health Secretary Sajid Javid has said they could go as high as double that in coming months.
In minutes of a meeting of scientific advisers published on Friday, they warn that acting earlier rather than later could reduce the need for stricter measures over a longer timeframe “to avoid an unacceptable level of hospitalisations”.
It added that any measures introduced must be clearly communicated.
The scientific advisors, led by Sir Patrick Vallance, say models forecasting the coming winter suggest Covid hospital admissions are “increasingly unlikely” to rise above the levels of January 2021 peak, but they are unsure of the impact of waning immunity and people’s behaviour.
There has been a noticeable dip in people saying they are wearing face coverings and latest figures from the ONS suggest more than half of British working adults are travelling to work.
Sage says making face coverings compulsory in some places is likely to also help reduce the spread of Covid and other winter viruses, such as flu.
It also notes the risks of high levels of the virus circulating in the UK, compared to other countries.
“Cases and admissions are currently at much higher levels than in European comparators, which have retained additional measures and have greater vaccine coverage especially in children,” the scientists say.
“Reducing prevalence from a high level requires greater intervention than reducing from a lower level.”
Another worry is the emergence of a new variant that becomes “dominant globally”, which they call “a very real possibility”.
And this winter, the advisors warn that the prospect of people being infected with Covid, flu and other respiratory viruses could be “a significant challenge”, saying people who show symptoms of an infection should stay at home to stop it spreading to others.
This message needs to come from government, employers, universities and schools to be most effective, they say.