During a visit to a vaccine manufacturing facility in Teesside on Saturday, Johnson said he was "optimistic" he could announce plans for a "cautious" easing of the rules when he sets out his "road-map" out of lockdown on Feb. 22.

However, he said ministers would have to look at the data "very, very hard" before taking any decisions as they did not want to be forced into a "reverse ferret" if the disease started to spread again.

In contrast, the CRG, in their letter, said that the government's "national priority" of re-opening schools in England by March 8 "must" be achieved.

By Easter, they said pubs, restaurants and other hospitality venues should be able to open in a way that is COVID-secure but still allows them to operate "in a commercially viable manner".

And by the end of April, when all the government's top nine priority groups, including all over 50s, should have been offered a vaccine, they said there will be "no justification" for any legislative restrictions to remain.

"COVID is a serious disease and we must control it. However, just like COVID, lockdowns and restrictions cause immense social and health damage and have a huge impact on people's livelihoods," the letter said.

"The vaccine gives us immunity from COVID but it must also give us permanent immunity from COVID-related lockdowns and restrictions," it said.

By March 8, the government's top four priority groups, which account for 88 percent of deaths and 55 percent of hospitalizations, will have had their first dose of the vaccine at least three weeks earlier allowing time for protection to kick in, it said.