Health Secretary Matt Hancock has refused to rule out the prospect of new Tier 4 restrictions in England if the current measures don’t go far enough to stop the spread of coronavirus.

He said the government would “rule nothing out”, adding: “We’ve always said all along that we take nothing off the table.”

When asked about the criteria for an area to exit Tier 3, Mr Hancock said: “The first thing that’s most important is that the case rate has to be coming down, and in particular we look at the number of cases amongst the over-60s because that’s the number that is likely to translate into hospital admissions and sadly into deaths.”

Mr Hancock also suggested a vaccine would not provide an escape route from the social restrictions until next year.

Quizzed on whether there would be some roll-out of a vaccine this year, he said: “Well, I don’t rule that out, but that is not my central expectation.

“The vaccine programme is progressing well.

“The leading candidates we’re in very close contact with. On my central expectation, I would expect the bulk of the roll-out to be in the first half of next year.”

It comes as ministers confirmed they were looking at reducing the time that people have to quarantine at home from 14 day to between ten days and a week.

Scientists have publicly criticised the mooted change, arguing it would risk allowing infected people to mix with others.

Paul Hunter, professor of medicine at the University of East Anglia, said: “Other things being equal, it would certainly increase the risk of transmission because the average incubation period for the disease is about five to six days, and only about 85-90 per cent of people by seven days will have actually developed ill.

“So if you cut that incubation period what would happen is that ten, maybe 15 per cent, of people who were infectious would ultimately (be) allowed to be back out in public.”

A similar measure has been put in place in France.

But Cabinet minister Mr Hancock pointed to France as an example of where a similar measure had been introduced.

He added: “So it isn’t about the compliance issue.

“It’s about the overall clinical judgment of what time is required for isolation.

“Obviously I’d rather have isolation as short as is reasonably possible because of the impact it has on people’s lives, but it must be safe.”

Meanwhile, the Welsh Government has said it will review a controversial ban on supermarkets selling non-essential items during a two-week “firebreak” lockdown which began on Friday.

Explaining the purpose of the review, Welsh Health Minister Vaughan Gething told Sky News: “We want the clarity on the principle that if there really are exceptional circumstances when someone needs what would otherwise be a non-essential item, that can happen as well.”