The prime minister said his administration was considering whether it needed to “go further” than the “rule of six” national restrictions put in place this week.
It comes as the R rate of the virus jumped again on Friday to between 1.1 and 1.4 and the daily number of positive cases went over 4,000 for the first time since May.
The PM admitted that a second lockdown was the “last thing anybody wants” but said the current measures would need to be kept “under review”.
During a visit to the Vaccines Manufacturing Innovation Centre construction site near Oxford, the PM told broadcasters: “Obviously, we’re looking very carefully at the spread of the pandemic as it evolves over the last few days and there’s no question, as I’ve said for several weeks now, that we could expect (and) are now seeing a second wave coming in.
“We are seeing it in France, in Spain, across Europe – it has been absolutely, I’m afraid, inevitable we were going to see it in this country.”
Reiterating the “rule of six” on social gatherings was meant as a “new buffer”, he admitted the latest figures spelled grim news for the country.
He said: “But as we look at this particular curve and what is happening now, clearly we are going to keep everything under review. I don’t want to get into a second national lockdown at all, it is the last thing anybody wants.”
Following the Eat Out To Help Out scheme introduced by the Treasury and the gradual relaxation of rules during the summer, Johnson was asked if the government had eased lockdown too quickly.
He said: “If you look at what’s happened over the last few months, I think the British people have done an amazing job.
“They got that peak under control, they brought it right down, they brought the number of infections right down by discipline and everybody adjusting our behaviours and the way we go about our lives – hands, face, space.
“And I think probably, truth to tell, what’s happened here and what alas has happened in so many other countries is that people find it difficult to keep this up.
“It is very difficult to maintain that kind of discipline for a long time and what you’ve seen is the disease starting to spread again among young people and that’s where it really started to kick off in France and Spain in those age groups and we are now seeing that here in this country.”
Asked about the possibility of a two-week October half-term in order to bring in a short lockdown, Johnson told reporters: “What I can certainly say about parents and schools is we want to keep the schools open, that is going to happen.
“We want to try and keep all parts of the economy open as far as we possibly can – I don’t think anybody wants to go into a second lockdown but clearly when you look at what is happening, you have got to wonder whether we need to go further than the ‘rule of six’ that we have brought in on Monday, so we will be looking at the local lockdowns we have got in large parts of the country now, looking at what we can do to intensify things that help bring the rate of infection down there, but also looking at other measures as well.”