England faced a wave of Covid hospital cases as high as the first peak if Boris Johnson went ahead with the June 21 'Freedom Day', government advisors believe.
The Prime Minister was forced to delay the easing of lockdown until July 19 after the Delta variant, said to be between 40% and 80% more transmissible than the Kent strain, had spread rapidly.
Now, new modelling by the Scientific Pandemic Influenza Group on Modelling (SPI-M) - a SAGE subgroup - has revealed just how risky scrapping all social distancing could have been.
Among the experts' worst case scenarios was that hospitalisations would reach around the peak of the first wave, when there were more than 3,000 new UK patients per day, compared to under 200 a day now.
Speaking at a Downing Street press conference on Monday, the PM said the average number of people being admitted to hospital in England had increased by 50% week on week, and by 61% in the North West, adding ministers feared it "may be the shape of things to come".
"Because we know the remorseless logic of exponential growth and even if the link between infection and hospitalisation has been weakened it has not been severed," he said.
The Prime Minister's official spokesman said earlier that throwing open the economy as planned could have meant a “surge in hospitalisations which would put unsustainable pressure on the NHS”.
The PM’s official spokesman said the extension to England's lockdown measures meant “thousands more deaths can be prevented” as it would give medics time to swiftly get more people jabbed.
The PM’s official spokesman confirmed: “SPI-M modelling suggests if we were to go ahead with step four on Monday, there is a possibility of hospitalisations around the peak of the first wave.”
He added: "The modelling suggests there could be significant pressure on the NHS at a time when it's dealing with backlogs”.
The spokesman outlined how there has been a “rapid acceleration in cases” and that the NHS' vaccine targets have been stepped up.
Advisors predicted that, if nothing were done, the country faced a larger wave this summer than they originally predicted in February, when the PM first unveiled the roadmap out of lockdown.
Back then, scientists forecast more than 30,000 further Covid deaths between February 2021 and summer 2022.
Nationally there are around 8,000 new cases per day, the highest since February, and ministers have been told cases are growing at 70% week-on-week and in around a third of the country are doubling every week.
Hospitalisations are increasing by 15% week-on-week and by 66% in the North West.
The modelling, which showed considerable uncertainty, was expected to be published today and came as worrying Public Health England data revealed how the virus was doubling in some parts of the country, most notably in the North West.
The sharp rise in cases also saw ministers issue snap 'don't travel' advice in Birmingham, Cheshire, Liverpool and Blackpool.
The government has officially brought forward its July 31 target to offer a first dose of vaccine to all over-18s in the England.
It now aims to offer all adults a first dose of the vaccine by July 19.
At the same time, ministers have set a new target to offer all eligible over-40s in England a second dose by July 19 at the latest.
To achieve this, all over-40s will now be offered their second dose eight weeks after their first, rather than the current 12 weeks.
The dose “interval” had already been shortened for over-50s, but that will now happen for people in their 40s as well.
The swifter rollout is aimed at reducing infection rates amongst younger people.
The spokesman said: “Vaccine effectiveness, especially after two doses, means thousands more deaths can be prevented if more people are jabbed.
“As the Chief Medical Officer has said, at some stage we are going to have to live with this virus as we do with flu.
“But when we have effective vaccines and a variant that needs two doses for maximum protection, it is right to allow more time to save lives.”
New Public Health England (PHE) data underlined that vaccines are “highly effective” in preventing hospital admission with the Delta variant of coronavirus, however.
Both the Pfizer/BioNTech and Oxford/AstraZeneca jabs are just as good at coping with the Delta variant first identified in India as the Alpha variant first identified in Kent, the data suggests.
Even after only one dose, vaccines were at least 71% effective against hospitalisation from the Delta variant.
The AstraZeneca vaccine was 71% effective (51-83%) while the Pfizer vaccine was 94% effective (46-99%) against hospitalisation from the Delta variant after one dose.
But the body did say that unvaccinated people have twice the risk of hospital admission with the Delta variant as the Alpha (Kent) variant.
And among those who are vaccinated, 12 people in every 100 may end up in hospital with Delta compared with eight for Alpha.