Professor Carl Heneghan, the director of the Centre for Evidence-Based Medicine at Oxford, told the BBC Today programme the country was in “deep, deep trouble” if lockdowns were repeated.
He added, “this is as good as it gets when you consider the predictable rise in winter pathogens at this time of the year”.
The intervention comes as ministers refused to rule out tougher restrictions.
Options said to have been presented to Boris Johnson include using non-binding guidance to urge caution, new restrictions on social gatherings, or even a full circuit-breaker lockdown.
Modelling from the government’s SAGE panel of experts suggests more stringent restrictions need to be brought in soon in England to stop 3,000 hospital admissions a day, reports the BBC.
But Professor Heneghan said “you have to have a balanced proportion when you get the models”, saying the data on Omicron remained unclear.
He added that he believed the government should trust people to “moderate their behaviour” calling it the “only sustainable policy”.
London has been hard hit by a surge of cases, with Mayor Sadiq Khan declaring a major incident in a bid to improve co-operation between public bodies to tackle the wave.
He told the Andrew Marr show on Sunday that he favoured tighter rules sooner rather than later, but that people should be able to enjoy Christmas.
“I think we should be able to celebrate Christmas safely,” he said.
“But I think sooner rather than later, we're going to have to look at social distancing, household mixing, because if we don't, the number of cases is only going one way."