London and parts of Essex and Hertfordshire will plunge into a Tier 3 coronavirus lockdown from 12.01am on Wednesday.
Health Secretary Matt Hancock gave a private briefing to MPs to confirm the move hours after they were warned cases are rising exponentially in the capital.
He told MPs the government had to act fast and it could no longer wait until Wednesday daytime, when the first routine review of the tiers system was due.
The move will shut down all restaurants, bars and cafes in the areas – except when they operate as takeaways – after the end of their shifts tomorrow night.
It was expected to be confirmed publicly by Mr Hancock at 3.30pm in a House of Commons statement. The exact areas of Essex and Hertfordshire are yet to be confirmed.
The announcement dramatically redraws the map of England, where previously only Kent was the large southern area in Tier 3.
Unless large parts of the north are dropped down a tier on Wednesday, it means well over 30million people in England will be living under the toughest restrictions.
Under Tier 3 rules, people will be banned from meeting people from outside their household or bubble, either indoors or outdoors – the only exception being open spaces like parks.
People will also be advised not to travel beyond their area except for essential reasons like work and school.
The announcement was brought forward from Wednesday after MPs were warned coronavirus cases in London are now “off the chart” .
MPs from London and Home Counties including Essex, Hertfordshire, Bedfordshire and Kent were briefed this morning by the government.
Kent is currently the only large part of southern England in Tier 3, with the capital still in Tier 2 which allows pubs to remain open. Most of the 23million in Tier 3 are in the Midlands and northern England.
But MPs were today told there is exponential growth of Covid-19 in the capital, and cases are also rising in places just beyond its borders.
Three sources said Thomas Waite, Director of Health Protection at the Joint Biosecurity Centre, told MPs case rates were “off the chart”.
An estimated 4,710 people in London tested on December 11 came back positive for Covid-19 – almost double the 2,402 on December 6.
The data for December 11 is still incomplete because it is so recent, and could be revised down. But it may also be revised up as more tests come back with results.
London hit 225 new cases per 100,000 in the seven days to December 8, up every day since a lockdown low of 155 per 100,000 on November 26.
Greenwich Council advised its schools to close tonight while Islington advised to shut from tomorrow, except for key worker and vulnerable kids.
Nearly all the secondary schools in Basildon, Essex, have also moved to full remote education, Essex County Council (ECC) has said.
London mayor Sadiq Khan has urged the Government to consider shutting all secondary schools and colleges early ahead of Christmas.
But the PM’s official spokesman said today: “We expect schools to be open to the end of term”.
This breaking news story is being updated.