Some kind of social distancing will need to stay in place "probably indefinitely" until Britain has a coronavirus vaccine - which could be a year away, a top government advisor has warned.
Britain's coronavirus lockdown will last at least another three weeks as the Government extends the shutdown at May 7 at 5pm today.
Amid a Cabinet split, some ministers want restrictions to be eased next month - with calls for coffee shops for example to reopen.
But Prof Neil Ferguson today warned some kind of restrictions would need to stay in place.
The Imperial College London professor is part of the government's scientific advisory group.
He led research which was crucial to imposing the lockdown three weeks ago, after warning failure to suppress the virus could lead to 250,000 deaths.
Prof Ferguson said it is likely the daily number of new infections peaked 2 weeks ago - but said we don't know how quickly numbers will decline and ir was "too early to relax" restrictions.
He told the BBC: "I should say, it's not going to be going back to normal.
"We will have to maintain some form of social distancing, a significant level of social distancing, probably indefinitely until we have a vaccine available."
He added: “It really requires a single-minded emphasis in Government and the health system on scaling up testing and putting in place the ability to track down cases in the community and contact-trace.
"Because without that, our estimates show we have relatively little leeway.
"If we relax measures too much then we'll see a resurgence of transmission.
"What we really need is the ability to put something in their place.
"If we want to open schools, let people get back to work, then we need to keep transmission down in another manner. "
Foreign Secretary Dominic Raab, standing in for PM Boris Johnson, will announce the extension at the No10 press conference.
He hosts Cabinet at 11am, joins a video link meeting of G7 leaders at 1.30pm then convenes COBRA at 3.30pm.
A statement to the nation is expected at 5pm.
Asked about the professor's call, Health Secretary Matt Hancock said: “He advises government, he's not in government.”
But there is a Cabinet split over exactly when to lift restrictions. And government advisors have been clear the lockdown cannot be eased until it is clear the UK is past the peak, not just at it.
Health Minister Nadine Dorries last night suggested the only way to free the UK from all social restrictions is to have a vaccine.
She tweeted: “There is only one way we can ‘exit’ full lockdown and that is when we have a vaccine. Until then, we need to find ways we can adapt society and strike a balance between the health of the nation and our economy.... There is more than one lockdown. Full, or the introduction of a relaxation/easement strategy - eventually to a full exit.”
And Health Secretary Matt Hancock warned today the virus will “run rampant once again” if lockdown is lifted too soon.
He told Sky News: “It is too early to say now that we should remove the measures.
“People can see that whilst we may be reaching a peak, the numbers aren’t coming down yet.
“We will not be returning straight back to exactly how things were before. This will take time.”
Shadow Health Secretary Jonathan Ashworth told the BBC: “If you want an exit strategy from a lockdown you either wait for a vaccine which is 18 months' time or you put in place a testing and tracing strategy.
"I'm not clear if the Government are putting in place a testing and tracing strategy at the moment.”
Prof Ferguson also called for a Brexit -style Whitehall department to coordinate the Covid-19 fightback.
He said: “I would like to see action accelerated. We need to put in place an infrastructure, a command and control structure, a novel organisation for this.
"I'm reminded by the fact we had a Department for Brexit for Government - that was a major national emergency, as it were - and we're faced with something which is, at the moment, even larger than Brexit and yet I don't see quite the same evidence for that level of organisation."
Asked whether the Government is moving towards having an exit strategy in place, Prof Ferguson said: "I'm not completely sure. I think there's a lot of discussion. I would like to see action accelerated.
"We need to put in place an infrastructure, a command and control structure, a novel organisation for this.
"I'm reminded by the fact we had a Department for Brexit for Government - that was a major national emergency, as it were - and we're faced with something which is, at the moment, even larger than Brexit and yet I don't see quite the same evidence for that level of organisation."
Prof Ferguson added: "There needs to be more co-ordination I think, yes. That may be going on, I don't have unique insight, but I think it could be enhanced."
Asked whether lockdown measures could be continued again in three weeks' time, he said: "I think we will take each step as it comes, I don't have a crystal ball to say how rapidly cases will decline.
"All I would say is we have limited leeway to release current measures unless we have something new to put in their place."
