Foreign Secretary Dominic Raab said it was “not sustainable” to keep the lockdown in place “permanently” but that the Government was monitoring the changes it was making.

Speaking at the daily Downing Street coronavirus briefing, Raab said: “It is true to say that making any changes inherently comes with some risk of spreading the virus compared with simply staying at home.

“But it is also true that staying in permanent lockdown is itself not sustainable on health grounds or economic grounds.

“That is why we have only eased measures where it can be done with the lowest risk possible.

“That’s also why we are watching the impact of every change we make very closely.”

England’s deputy chief medical officer Professor Jonathan Van-Tam said the country had to prepare in case Covid-19 came back in the autumn and winter.

Only once there was a vaccine that is “really capable of suppressing disease levels” will the country be “out of this”.

“So from that perspective we may have to live, and learn to live, with this virus in the long-term, certainly for many months to come if not several years,” he said.

He said more information was needed on the seasonality of Covid-19.

“One of the things that’s very clear with flu viruses is that they come in our cold winters and the levels of transmission and circulation decline over the summer months.

“The data we have on other coronaviruses we have looked at very carefully, and it’s not clear that these coronaviruses are as seasonal as influenza.

“But there may be an element of seasonality and it may well be that the autumn and winter conditions provide a better environment for the virus to then do its work again.”