Video report by ITV News Political Correspondent Carl Dinnen
The leaders of all four UK nations will make a decision on whether to tighten Christmas coronavirus rules on Wednesday after meeting to discuss the situation earlier today.
ITV Political Editor Robert Peston understands Boris Johnson has decided against changing the current plan for Christmas for people who live in England.
The meeting today was held by Michael Gove and representatives from the three other nations of the UK to discuss tightening the rules over the festive period.
If the prime minister has decided not to change course then it is possible the UK will not have a unified approach to Christmas.
The current rules allow up to three households to mix for five days over the Christmas period.
ITV News Political Editor Robert Peston describes why he thinks the rules in England won't change
Downing Street said a relaxation of coronavirus restrictions is being kept "under constant review".
The prime minister's spokesperson said: "We have set out the Christmas guidance and we have been clear around the need for people to remain cautious and vigilant throughout the Christmas period...
"As we have done throughout the pandemic we keep all advice under constant review."
A Welsh Government source said: "The leaders of the devolved administrations and Michael Gove met this evening to discuss the arrangements over the Christmas period. They will reconvene tomorrow to confirm the position."
Scientists, medical professionals and politicians have been urging the government to reconsider its plan amid rising Covid-19 cases, with Sir Keir Starmer the latest.
ITV News Health Editor Emily Morgan discusses what the government could do
The Labour leader demanded an urgent review of the relaxation of Covid rules over Christmas in a letter to the prime minister.
In a clip he said the "only responsible thing" for the government to do "is to look again at the Christmas restrictions and see whether they need to be toughened up".
In his letter, Sir Keir added: "I understand that people want to spend time with their families after this awful year, but the situation has clearly taken a turn for the worse since the decision about Christmas was taken.
"It serves no-one for politicians to ignore this fact.
"It is my view that you should now convene Cobra in the next 24 hours to review whether the current relaxation is appropriate given the rising number of cases."
Sir Keir said the PM would have his "full support" if he did decide to scrap the plan for relaxations at Christmas.
Earlier the British Medical Journal (BMJ) and the Health Service Journal (HSJ) said plans to ease rules at Christmas should be abandoned in order to bring down Covid-19 numbers ahead of a "likely third wave"
They urged the government should "reverse its rash decision to allow household mixing and instead extend the tiers over the five-day Christmas period in order to bring numbers down".
In their joint editorial, they added: "We are publishing it because we believe the government is about to blunder into another major error that will cost many lives."
The PM's spokesperson said the plan - which had been agreed by all four UK nations - was being implemented because the government wanted to "give families and friends the option to meet up".
But he said people should remember that while the guidelines set out what people can do, "it isn't saying is this is what people should do".
"It is up to people to remain cautious and vigilant throughout the period," he added.
He said people should "try to keep numbers down and don't do things that are unnecessary" to avoid behaviours that would spread coronavirus over the festive period.
He added: "It is imperative that people remain cautious and vigilant throughout the Christmas period."
Northern Ireland's Chief Scientific Adviser Professor Ian Young urged anyone who was planning to take advantage of the relaxations on household gatherings over Christmas to stop socialising now.
"What I'd be saying to anybody who is planning to bubble, particularly if you're going to be seeing an elderly or vulnerable relative, for the next 10 days you should be seeing nobody else," he said.