A Norfolk MP and minister today refused to rule out social distancing measures remaining in place all year.

South West Norfolk MP and international trade secretary Liz Truss was speaking on Sky's Sophy Ridge on Sunday, after reports the vaccine which has already been given to almost 8.5m people may not be able to completely halt the corona virus in its tracks.

The warning comes from scientists on the government's Scientific Advisory Group for Emergencies (SAGE) , who warn of a third wave of deaths, unless the jab proves at least 85pc effective in combating infections.

Prime Minister Boris Johnson is hoping falling Covid cases will allow gradual lifting of lockdown, with pupils allowed to return to school from March 8, followed by non-essential retailers opening in April, the hospitality sector in May and life returning to normal by the autumn.

But when asked about the timescale by Sky's Sophy Ridge, Ms Truss told said: "I don't want to make predictions about the situation in the autumn, I think it's far too far away. Long-term predictions in what is a very, very unpredictable situation are not wise."

Public Health England's Dr Susan Hopkins warned that relaxing lockdown measures would have to be done "very slowly, very cautiously" to avoid a surge in infections.

"We have learnt, as we did on the first occasion, we have to relax things really quite slowly, so that if cases start to increase we can clamp down quite fast," she told BBC One's Andrew Marr Show.

"The NHS is going to be under pressure until the end of March, as normal in winter, but even more so with the amount of inpatients they still have with Covid-19.

"Any releases that we have will have to happen very slowly, very cautiously, watching and waiting as we go, with a two-week period to watch and see the impact of that relaxation because it takes that to see what's happening in the population."

Asked if there was evidence the vaccination programme was beginning to reduce infections, she added: "We are seeing declines in all age groups at the moment.

"We're starting to see declines in the over-70s and over-80s. It's a bit early to say whether those declines are directly related to the vaccine."