Southwark is moving into Tier Three, the highest Covid alert level, along with the rest of Greater London on Wednesday.
The move, confirmed by the health secretary Matt Hancock in the commons shortly before 4pm, means hospitality venues must close except for takeaway.
Households are banned from meeting with one another, except those in a support bubble, except in limited circumstances such as outdoor public spaces.
“This means people can only see friends or family they don’t live with, or are in a support bubble with, in outdoor public places and of course in line with the rule of six,” said Mr Hancock.
“Hospitality settings must close, except takeaway and delivery, and people must avoid travelling outside their area, and reduce the number of journeys they make wherever possible.
“I know this is difficult news, and it will mean plans disrupted. For businesses affected, it will be a significant blow.
“But this action is absolutely essential.”
It comes as Mr Hancock said scientists had identifed a new variant of Covid which may be associated with the faster spread in the south of England.
There is no evidence the variant strain is resistant to a vaccine, he said.
Southwark’s council leader said the move was the right choice to take, but called for greater support.
“With COVID-19 cases rising so quickly across London it is right that our city moves to Tier 3 to protect lives, but it is also essential that Londoners (& people in all other areas in Tier 3) recive [sic] the economic support package needed to protect livelihoods and businesses,” said Cllr Kieron Williams.
Bermondsey and Old Southwark MP, Neil Coyle, said the harsher restrictions were an admission from the government that its current approach was not working.
“The Government is moving towards Tier3 for London which is to acknowledge that existing measures are not working. But the Government is yet to say how it will fix/improve measures,” he said.