Boris Johnson may be forced to reimpose lockdown restrictions if Covid cases continue rising into the autumn, former health secretary Jeremy Hunt has warned.

With most statutory controls in England due to end on Monday, Mr Hunt said the situation facing the NHS is “very serious” with rapidly increasing numbers of hospital admissions.

“The warning light on the NHS dashboard is not flashing amber, it is flashing red,” he told the BBC Radio 4 Today programme.

His warning came as one scientist advising the Government said the country could be facing a “protracted period” of rising cases running into the autumn.

Professor John Edmunds, of the London School of Hygiene and Tropical Medicine and a member of the Scientific Advisory Group for Emergencies (Sage), said new infections could reach 100,000 a day within weeks.

Mr Johnson has repeatedly said he wants the lifting of lockdown on so-called “freedom day” to be “irreversible”, but in recent days ministers have begun to sound more cautious.

While social-distancing rules in England will come to an end, Government guidelines advise face masks should still be worn in enclosed spaces such as in shops and on public transport, while pubs and bars should be table service only.

I think this wave of the epidemic will be quite long and drawn out

Mr Hunt, chairman of the Commons Health and Social Care Committee, said the way people behave as controls end will be crucial in determining the path of the pandemic over the coming months.

He pointed to the examples of Israel and the Netherlands, which have been forced to reintroduce controls despite high levels of vaccination like the UK.

“Covid hospital patients are doubling every two weeks. That means we are heading for 10,000 Covid hospital patients by the end of August, which is about 20 times higher than this time last year,” he said.

“I think coming into September we are almost certainly going to see infections reach a new daily peak going above the 68,000 daily level which was the previous daily record in January.

“If they are still going up as the schools are coming back I think we are going to have to reconsider some very difficult decisions. How we behave over the next few weeks will have a material difference.”

Prof Edmunds said that without the social-distancing measures which brought the first two waves of the pandemic under control the virus would continue to spread.

“I think this wave of the epidemic will be quite long and drawn out,” he told the Today programme.

“My hunch is that we are looking at a high level of incidence for a protracted period right through the summer and probably through much of the autumn.

“We started easing restrictions before everybody was vaccinated. That is going to lead to infections in the unvaccinated people – primarily, in this instance, the younger individuals.

“We are at about 50,000 (infections) a day now. The epidemic has been doubling roughly every two weeks, and so if we allow things as they are for another couple of weeks you could expect it to get to 100,000 cases a day.”

Mark Woolhouse, professor of infectious disease epidemiology at Edinburgh University, who advises the UK and Scottish governments, said there could be a “very large wave” of new infections.

He said England should have followed the example of Scotland and kept some infection control measure in place.

“What I have been concerned about for many months is that if the unlocking really is a big release… then there’s potential for a very large wave indeed,” he told Times Radio.

“This idea that it would be a final ‘freedom day’ was, I have to say, somewhat naive. The public health expectation was that we would need additional measures to keep the rate of increase of cases under control.”

Mr Hunt said the Government needs to make urgent changes to the NHS Covid app amid evidence people are deleting it due to the high numbers being “pinged” and told to self-isolate.

“The risk with that app is that it is beginning to lose social consent and so we should either make it less sensitive or move to a system where you have to get a test when you are pinged,” he said.

“The risk is that if people are deleting the app then you can’t even ping them to ask them to have a test.”