Prime Minister Boris Johnson is set to announce a second national lockdown for England as the UK passed one million Covid-19 cases.
Non-essential shops and hospitality will have to close for four weeks, sources told the BBC.
But unlike the restrictions in spring, schools, colleges and universities will be allowed to stay open.
It comes as documents suggested the UK was on course for a much higher death toll than during the first wave.
The lockdown is also expected to include restrictions on travel and is due to come into force on Thursday, lasting until 2 December, BBC political correspondent Nick Eardley said.
Takeaways will be allowed to stay open as pubs, bars and restaurants close and it is expected people will be told they can only meet one person from outside their household outdoors.
- ‘A new lockdown will be far worse for businesses’
- Covid spreading faster than ‘worst-case scenario’
- Winter virus plans revealed in leaked Sage report
The prime minister is due to lead a news conference later, after holding a cabinet meeting to discuss the coronavirus response.
He is set to be joined by England’s chief medical officer Chris Whitty and the government’s chief scientific adviser Sir Patrick Vallance for the briefing.
The UK recorded another 21,915 confirmed coronavirus cases on Saturday, bringing the total since the pandemic began to 1,011,660.
Another 326 people were reported to have died within 28 days of a positive test.
The UK is the ninth country to reach the milestone of a million cases – after the US, India, Brazil, Russia, France, Spain, Argentina and Colombia.
But the true number of infections is expected to be higher due to a lack of widespread testing at the start of the pandemic.