Here's everything you need to know about the update, which was issued at about 6pm on Friday, September 18, 2020.
Where is the 'R number' now for the UK?
The Government’s Scientific Advisory Group for Emergencies (Sage) said the R number – representing the number of people an infected person will pass the virus to – has risen to between 1.1 and 1.4, meaning cases could rise very quickly.
PM: 'We're now seeing a second wave coming in to the UK'
As ministers announced tough new restrictions affecting 13.5 million people, Mr Johnson said they would “keep everything under review”.
“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,” he told reporters during a visit to the Vaccines Manufacturing Innovation Centre construction site near Oxford.
“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.”
What's the latest on coronavirus cases in the UK?
Public Health England (PHE) warned that data published on Friday (September 18) could be a sign of “far worse things to come”, as the Office for National Statistics (ONS) said cases are thought to have almost doubled in a week to 6,000-a-day in England.
What has the reaction been to the latest R figure?
Kevin McConway, emeritus professor of applied statistics at the Open University, described the latest R figure as “undoubtedly concerning”.
He said: “Even at growth rates within the estimated range, the number of new cases could grow to high levels quickly if the interventions are not sufficiently effective.”
It comes as ministers discuss whether further national restrictions are needed, such as forcing pubs and restaurants to close at 10pm or curbs on people socialising.
Boris Johnson speaks out on reports of a second national lockdown
The Prime Minister insisted that he did not want a second national lockdown, but said it was essential that people followed social distancing guidelines – including the new “rule of six”.
“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,” he said.
“I don’t want to go into bigger lockdown measures at all, we want to keep schools open and it is fantastic the schools have gone back in the way they have. We want to keep the economy open as far as we possibly can, we want to keep businesses going.
“The only way we can do that is obviously if people follow the guidance.”