The NHS could be overwhelmed “within weeks” without drastic action to tackle the spread of Covid-19, experts have warned.

Ministers fear that hospitals could fill up with rising coronavirus admissions.

Without action to stem the tide of cases, it would be “impossible” for the health service to cope in the coming weeks, academics said.

Sir Jeremy Farrar, director of the Wellcome Trust, said: “Doctors and scientists agree that none of the current restrictions have been enough to stop the virus spreading.

“Without a change, the NHS would have been overwhelmed within weeks and it would have been difficult if not impossible to cope in the winter months with the inevitable increase in caring for people with Covid as well as non-Covid illnesses.

“There’s absolutely no doubt that many more of us would have seen loved ones die, suffer with long-term Covid symptoms or from other illnesses.

“The only way to get things back to normal quickly is to get the virus under control as soon as possible.”

Dr Shaun Fitzgerald, Royal Academy of Engineering visiting professor at the University of Cambridge, added: “None of us want this at all.

“But it now seems there is no choice if we are to avoid letting thousands and thousands more die, and the health service swamped to an extent that even non-Covid patients are seriously affected.”

The news comes as the UK recorded more than one million lab-confirmed cases of coronavirus since the start of the outbreak, according to Government data.

And hospitals are feeling the pressure as cases rise.

There are now almost 11,000 people in hospitals across the UK – including 978 on ventilators.

And many hospitals are treating more patients than they were at the height of the first wave of the pandemic.

A number of hospitals have been forced to postpone some of their other work to cope with the pressures of Covid-19 patients.

Experts said last week that it was “not unrealistic” to think that there could be 25,000 people in hospitals by the end of November.

Danny Mortimer, chief executive of the NHS Confederation, said: “NHS leaders in Covid-19 hotspot areas are telling us they are very concerned about soaring infection rates, with hospitals, mental health services and community services under huge pressure, especially with the prospect of a tough winter on the cards.

“If we are to avoid even more loss of life, people becoming seriously unwell, and significant disruption to the NHS’s broader services, it’s vital that transmission of the virus can be cut and some of that pressure is eased.

“The NHS is not, and has never been, a Covid-only service, so while the infection is spreading, our members are telling us they want to minimise disruption to their non-urgent activity. However, to continue services, they need the public to play their part in following the necessary infection control measures, including in primary and community care, where clinicians continue to provide face-to-face appointments.”

Along with rising case numbers and hospital admissions, there has been a rise in the number of deaths.

In September, the Government’s chief scientific officer warned that the UK could be facing 50,000 new Covid-19 cases a day by mid-October, leading to 200 deaths a day a month later.

But the Government said a further 326 people had died within 28 days of testing positive for Covid-19 as of Saturday.

Figures published by the UK’s statistics agencies for deaths where Covid-19 has been mentioned on the death certificate, together with additional data on deaths that have occurred in recent days, show there have now been 62,000 deaths involving Covid-19 in the UK.

But one expert said that a four-week lockdown “may not be enough” if people do not comply with the new restrictions.

Dr Julian Tang, honorary associate professor and clinical virologist in respiratory sciences at the University of Leicester, said: “With the virus being so widespread and numbers of cases increasing so quickly now, a four-week lockdown my not be enough – unless everyone complies as comprehensively as possible with the restrictions.”

Sir Jeremy added: “My experience from other virus outbreaks is that the second wave is always harder. Everyone is worn out, healthcare workers in particular. It can feel more hopeless the second time round. We wish it would just go away. But we have to remember it isn’t hopeless and what we do will make a difference.

“The sooner we act, the sooner we can start to recover. It will be a very difficult few weeks now and no one can underestimate the toll that will take on people.

Professor Sir Robert Lechler, president of the Academy of Medical Sciences, said: “We are all fatigued by this virus and weary of adjusting our lives around Covid-19, but I believe we have no other choice than to move back into a national lockdown.

“All of the evidence points towards this being the only step we can take together to prevent the high number of deaths predicted.

“A national lockdown will buy us some time to get back on track and bring the R number down. It will not be a complete fix, but it is a crucial way for us to regain control, regroup and develop further interventions.”