The Prime Minister said that although the case rate in the capital was “flattening”, he had seen new data this morning that showed it was doubling in the nation as a whole.
In addition, MPs are lobbying the PM to ensure London is returned to Tier One, the lowest level of restrictions, in recognition of its improvements.
But Mr Johnson said it was “no accident” that London and some other areas were seeing a lower gradient of cases. “This is because of the heroic collective efforts and sacrifice that the people of London, and elsewhere the Northeast, [where] it’s flattening,” he said.
“That is because people are following the guidance, making a huge effort to distance themselves.
He went on: “Yet it is still true that overall the virus is still doubling in this country and I saw the data this morning.
“Alas, it’s doubling in some places faster than elsewhere. About one in 90 people now have the virus. One in 90, that’s a lot of people, alas, and we’re going to see those cases, sadly, feeding through into our hospitals.”
Mr Johnson argued that there could be no easing of the national effort, despite news of a vaccine that millions of doses could be administered before Christmas.
He said London’s improvement showed that “collective action, all of us pulling together really can work” and added: “What we’ve got to do now in the run up to Christmas, and the run up to December 2, is to make sure that we do follow this guidance, so we can all have as normal a Christmas as possible.”
London’s infection rate is 149 cases per 100,000 of population, according to the most recent official data, which is significantly below other major cities. The figures for other cities include Manchester, 463; Birmingham, 321; Bristol, 408; Leicester, 414; Glasgow, 300; Cardiff, 288; Belfast, 269.
The call to review restrictions sooner if it is safe to do so was made by former Cabinet minister Theresa Villiers, the City of London, business groups London First and London Chamber of Commerce and Industry, plus dozens of business people battling to save jobs and survive the lockdown.
“I remain buoyantly optimistic about the prospects of this country next year,” he told the news conference.
“I just don’t want to let people run away with the idea that this development is a home run, a slam dunk, a shot to the back of the net, yet.
“There is a long way before we have got this thing beat.”
Deputy chief medical officer Professor Jonathan Van-Tam said it could take over a month from people receiving the first dose of a vaccine to having full protection from the virus.
He said some protection could begin immediately but full protection required two doses spaced up to 28 days apart and up to an additional 14 days for the body to respond.
And he warned there were many unknowns. “Whether they reduce transmission is something we do not know yet and that is a crucial factor that will understand how far vaccines take us towards to the kind of future that you aspire to.
“We are working on that. We are very aware of what is needed.”