London will face Tier 2 coronavirus restrictions from Saturday.
It means millions in the capital will be banned from meeting people from other households indoors, whether that’s in their home or in a pub.
Londoners have also been advised to avoid public transport and reduce the number of journeys they make where possible.
Health minister Helen Whately told London MPs of the decision during a call this morning.
London mayor Sadiq Khan said COVID-19 is “spreading rapidly in every corner of our city”, with a “significant number” of boroughs reporting an average of 100 cases per 100,000 people.
“Nobody wants to see more restrictions, but this is deemed to be necessary in order to protect Londoners by myself, London council leaders and ministers,” he said.
Mr Khan said that “action on a national scale” was still required, calling for a “short national circuit breaker” lockdown.
This “could save thousands of lives and drive the virus down to manageable levels”, he told the London Assembly.
On Tuesday, Mr Khan told Sky News that further restrictions were “inevitable” as hospital admissions and infection rates were “going in the wrong direction”.
He also wrote to the prime minister, telling him: “None of us want more restrictions in London but given the increase in infection rates and the lack of testing we have little choice.”
The London-wide average infection rate was 78 new cases per 100,000 people in the week to 9 October.
However, it varies widely across boroughs. Ealing had the highest rate at 119 new cases, while Bexley had 51.6.
That is still much lower than the infection rate in many parts of northern England, such as the Liverpool area, which is under the most severe Tier Three restrictions.