The government is holding further talks with the devolved nations over Christmas rules, as Boris Johnson resists demands to rethink the relaxation of COVID-19 restrictions over the festive period.
He is now facing MPs in the Commons and will later address Tory backbenchers and declare his opposition to dropping plans for three households to meet up from 23 to 27 December.
But the prime minister is expected to urge people to self-isolate before joining up with other households and the government is poised to issue tougher guidance for the festive period.
Besides isolating before meeting up, the new guidance is expected to include a plea to stay local where possible and think carefully before meeting elderly and clinically vulnerable people.
Housing Secretary Robert Jenrick told Sky News that people should "use their own personal judgement and think carefully" about what is right for their family over Christmas.
Citing the rise in infections in the United States following the Thanksgiving holiday, Mr Jenrick acknowledged that allowing different households to meet up over the festive period "will have consequences".
"This is a virus that thrives on social interaction. So bringing more people together, even for this relatively short period of time, is not cost free," he said.
"It will have consequences in terms of increasing the rate of infection."
Mr Jenrick added: "But these are the sorts of judgements that people need to weigh up - how much do they want to bring members of their broader family together at Christmas. Or whether they think, on this occasion, let's just keep it small and we can meet up in the spring.
"Easter can be the new Christmas for some people."
Mr Johnson clashed at PMQs with Labour leader Sir Keir Starmer, who has demanded an urgent review of Christmas COVID rules and claims the tier system has failed to control the virus.
Labour's shadow communities secretary Steve Reed told Sky News: "It all looks a lot riskier today, in light of the increase in the rate of infection, than it looked when the decision was taken."
He added: "The last thing we want is to have a free-for-all over five days of Christmas, if that then results in a protracted lockdown in the new year."
But speaking to the 1922 Committee of Conservative MPs later, the prime minister will attempt to reassure backbenchers who claim a change in the rules at this stage would be met with widespread defiance.
Mr Johnson's "carry on Christmas" message, defying pressure from medics to scrap the five-day relaxation, emerged after Cabinet Office minister Michael Gove held talks with the leaders of Scotland, Wales and Northern Ireland.
After the talks, a UK government source said: "There are no plans to change the regulations in England. We're keen to maintain a UK-wide approach and will have further discussions with DAs [devolved administrations] tomorrow morning."
Later, commenting on England, a government source told The Daily Telegraph: "We've set out the rules. People know what they are. It would be wrong to change them this close to Christmas when they have made plans."
But the source added: "However, the prime minister will want to be clear that minimising the risk to themselves and their loved ones is something they should consider."
And Mr Jenrick told Sky News: "Our position is clear I hope, the legal framework will continue."
In his talks, Mr Gove found little appetite for changing the Christmas plans.
Welsh First Minister Mark Drakeford described the four nations approach as a "hard-won agreement" and said he would "not lightly put it aside".
A Scottish government spokeswoman said: "The four nations call was a good opportunity to review the position on Christmas and discuss whether the messaging or guidance requires to be reinforced."
But earlier, First Minister Nicola Sturgeon told the Scottish parliament: "I do think there is a case for us looking at whether we tighten the flexibilities that were given any further, both in terms of duration and numbers of people meeting.
"And I will consider the views of the other nations - if we can come to a four nations agreement, I think that would be preferable.
"If that is not possible, then of course we will consider within the Scottish government what we think is appropriate."
A snap UK-wide YouGov poll suggested 57% of respondents believed the relaxation of COVID rules over Christmas should be dropped and only 31% said the easing of rules over the festive period should go ahead.
As well as reviewing the Christmas rules, the government is also reviewing the three-tier system in England, with some areas outside London, which is now in Tier 3, possibly moving from Tier 3 into Tier 2.
In the Commons on Monday, Health Secretary Matt Hancock gave a strong hint to the former Labour cabinet minister Hilary Benn that Leeds could be about to move from Tier 3 to Tier 2.
Mr Benn said since the recent national lockdown began the infection rate in Leeds had fallen from over 400 cases per 100,000 to less than 140 and the number of COVID patients in hospital has declined by 45% in the past month.
Mr Hancock replied: "You have made a typically wise intervention ahead of the decision making on Wednesday as to the wider tiering decisions for the rest of the country."
Later, at a Downing Street news conference, Mr Hancock hinted that Manchester, Newcastle, the Tees Valley, Bristol and Nottingham may also have some hope of following Liverpool out of Tier 3 into Tier 2 in the review.
He said all had shown the same pattern of strong local resolve to cut infections, as the Liverpool city region had when it secured its move to the lower tier. "We can do this, but we need to do it together," Mr Hancock said.