Pubs, bars and restaurants in England will be forced to close by 10pm from Thursday as part of restrictions to tackle the sharp rise in coronavirus cases.
The prime minister is set to address the nation on Tuesday evening to outline new measures which will include restricting the hospitality sector by law to table service only.
Boris Johnson will chair meetings of the Cabinet and the Cobra emergency committee – including the leaders of Scotland, Wales and Northern Ireland and will make a statement in the House of Commons – ahead of a live, televised address at 8pm.
The Scottish and Welsh governments have yet to announce whether they will implement the same measures, but Northern Ireland has banned households mixing indoors from 6pm on Tuesday.
First Minister Nicola Sturgeon has warned Scotland that they should brace for additional measures as soon as Wednesday.
In Wales, more than 840,000 people are living under tougher restrictions and are no longer able to meet members of their extended households indoors.
Mr Johnson is expected to set out further ways the country can confront coronavirus in line with the scientific advice.
The "rule of six" restriction will remain in place, except in places that are under local restrictions where household gatherings are restricted.
The 10pm curfew in pubs, bars and restaurants is used elsewhere in local lockdowns, including in north east England and Bolton, which has the highest number of new coronavirus infection rates.
The latest restriction comes after the UK’s four chief medical officers recommended raising the Covid alert level from three to four – the second highest – indicating the “epidemic is in general circulation; transmission is high or rising exponentially”.
On Monday, chief medical officer Professor Chris Whitty and chief scientific adviser Sir Patrick Vallance warned the UK could see 50,000 Covid-19 cases a day by mid-October and a daily death toll of 200 or more a month later unless urgent action is taken.
They said the number of cases is currently doubling around every seven days.
A Number 10 spokesperson said: “No-one underestimates the challenges the new measures will pose to many individuals and businesses.
“We know this won’t be easy, but we must take further action to control the resurgence in cases of the virus and protect the NHS.”
The UK currently has the third highest infection rate in Europe with a rate of 70.7 cases per 100,000 population.