New coronavirus restrictions are being introduced in Wales, Scotland and Northern Ireland as leaders try to combat rising COVID-19 cases, but politicians in England are unlikely to discuss further measures until Monday.
From Boxing Day, a maximum of six people will be allowed to meet in pubs, cinemas and restaurants in Wales.
A total of 30 people will be allowed at indoor events while 50 people will be allowed at outdoor events.
Two-metre social distancing is being required in public premises and offices, and nightclubs will close.
The rules, in force from 6am, are a revised version of alert level two.
In Scotland, large events will have one metre physical distancing and will be limited to 100 people standing indoors, 200 people sitting indoors and 500 people outdoors.
A day later, up to three households can meet with a one metre distancing between groups at indoor and outdoor venues like bars, restaurants, theatres, cinemas and gyms.
Table service is also needed at places where alcohol is served. Northern Ireland is also bringing in restrictions on Boxing Day and December 27, with indoor standing events no longer permitted and nightclubs closing.
Socialising will be reduced to three households while up to six people can meet in pubs, bars and restaurants. Ten people will be allowed if they are from the same household.
Only table service will be available. A two-metre social distancing rule will be in place in public premises and offices.
Prime Minister Boris Johnson has yet to announce any further rules for England but indicated he will not hesitate to act after Christmas if required amid rising cases of the Omicron variant.
The Government may choose to issue new voluntary guidance on limiting contacts rather than risk another damaging Tory rebellion by recalling Parliament to impose new rules beyond the existing Plan B measures.
It is understood a Covid O meeting is yet to be scheduled as ministers await further data, but No 10 did not rule out the possibility one could take place on Monday.
However, it is understood school closures are not being considered for January.
A source close to Education Secretary Nadhim Zahawi said: “The PM and Nadhim are fully committed to keeping schools open, and there’s a shared commitment across Government to do so.
“Education is a top priority and school closures are not something being considered.”
Graham Brady, chairman of the powerful 1922 Committee of Tory MPs, told the Observer it was “time to move on from the lazy assumption that Government has the right to control our lives”, adding that Britons should “take responsibility for our own lives once again”.
Charles Walker, a former vice-chairman of the committee, told the newspaper he hoped emerging data would support maintaining the current course of action.
“I think the PM has done extremely well to weigh up the information, hold his nerve and get us to this point,” he added.