The summer Covid peak could last for six weeks after lockdown rules ease and put a "considerable burden" on the NHS, a Government SAGE expert has said.
Professor Graham Medley, who chairs the modelling group SPI-M, warned of the challenges facing the health service with the pinnacle of the third wave of the virus expected to continue for weeks.
Daily deaths could soar to 100 to 200 at the peak, with between 1,000 and 2,000 hospitalisations per day, the Government's scientific advisers have predicted.
But uncertainty about how quickly people will return to their pre-pandemic habits has left experts unsure about the size of the next wave.
Boris Johnson confirmed plans to press ahead with lifting England's remaining lockdown rules on July 19 but the PM urged people to exercise caution with their new found freedoms.
Get a daily morning politics briefing straight to your inbox. Sign up for the free Mirror Politics newsletter
There is some disquiet in Westminster about the decision to axe restrictions while cases remains high, with Health Secretary Sajid Javid admitting infections could soar to 100,000 a day.
But he told MPs that vaccines had weakened the link between cases and hospitalisations and expressed confidence that the jab would protect people from serious illness.
Prof Medley told BBC Radio 4's Today programme: "We've never seen a peak before that hasn't been controlled.
"The intention is not to introduce a lockdown for this peak. Then we are going to see a natural peak and that may well be long and disseminated.
"So even if we don't get up to very high numbers, the numbers that we get up to might last for several weeks, six weeks or so, in which case there's still a considerable burden on healthcare.
"So, although we might not get over 2,000 admissions a day, if that lasts six weeks then that's a lot of people."
Prof Medley also said that mask-wearing "probably won't do any good" when legal requirements to wear face coverings are axed next week.
He said: "I personally will wear a mask to protect other people.
"I think it's quite a reasonable thing to do; it doesn't have a huge imposition in terms of economic impact or in terms of freedom, and I think there is evidence to suggest it does good, but only if everybody does it.
"So I think that, without the mandation, then we end up with a situation where even if the majority of people, let's say 70% of people wear a mask, will that actually do any good because of the 30% who don't?
"I think that is something which still needs to be determined and discussed.
"I understand the Government's reluctance to actually mandate it. On the other hand, if it's not mandated it probably won't do any good."
