A deal to allow families to meet over Christmas has been reached by the leaders of all four UK nations.
A source told the BBC that details on how Covid restrictions will be relaxed will be announced shortly.
Scotland's first minister said she would "continue to ask people to err on the side of caution".
BBC Scotland's chief political correspondent said three households will be allowed to meet indoors over five days between 23-27 December.
Glenn Campbell said they will be able to meet in each other's homes, at a place of worship and in an outdoor public space. But the groupings must be "exclusive", meaning you cannot get together with people from more than two other households.
He added the leaders of the nations are expected to urge Britons to use any new flexibility sparingly because public health officials are worried Christmas get-togethers could cause a January spike in Covid cases.
Speaking ahead of a meeting of the UK government's emergency committee Cobra, Welsh First Minister Mark Drakeford cautioned any extra freedoms would not be an instruction to do "risky things".
Scotland's First Minister Nicola Sturgeon also stressed any changes would be "temporary" and "limited".
She said that the "details" may differ "to reflect different circumstances in each nation", such as what the definition of a "household" might be.
She added: "I know everyone has a desire to see loved ones over the festive period.
"However, there is also a very real and a very legitimate anxiety that doing so could put those we love at risk, set back our progress as a country and result in unnecessary deaths and suffering."
Meanwhile, the government has recorded another 608 deaths of people in the UK who have died within 28 days of a positive Covid test. There were also a further 11,299 cases of people testing positive for coronavirus.
What to do about Christmas divides opinion.
Increased mixing indoors will certainly mean there is greater transmission of the virus.
But, as chief medical adviser Prof Chris Whitty said on Monday, there is a balance to be struck between the harm the virus can cause and the societal and economic impacts of trying to control it.
He called for a "public-spirited approach".
By that he means adhering to the restrictions in the lead up to Christmas, being responsible with the opportunity the relaxation gives people and then immediately switching back to compliance.
If that happens any impact could be minimised - and, of course, it will be up to individuals to decide just how much they mix within the rules.
These are very fine judgement calls by ministers.
They hope Christmas will provide respite and help steel the public for what is clearly going to be a long, hard winter.
They also feel they have little choice, believing large numbers of people would ignore pleas not to mix and this way they can provide advice on how to enjoy Christmas as safely as possible.
But there is also the risk by sanctioning it there will be more mixing than there would have otherwise been.
Prime Minister Boris Johnson has acknowledged there would be risks of letting people meet over Christmas but said families should have the chance to reunite.
Transport Secretary Grant Shapps earlier said Christmas travellers should plan journeys carefully and prepare for restrictions on passenger numbers.
Referring to domestic travel during the festive period, Mr Shapps urged those travelling on public transport to pre-book tickets as the capacity of services remains reduced to allow for social distancing and as a result of staff self-isolating.
Mr Shapps also highlighted Network Rail's plans for a series of upgrades and routine maintenance across Britain between 23 December to 4 January.
He told BBC Radio 4's Today programme: "I would appeal to people to think very carefully about their travel plans and consider where they are going to travel and look at the various alternatives available."
Mr Shapps added that people who live in areas placed in the highest tier of restrictions in England should avoid leaving their region entirely.
Mr Shapps said confirmation of the exact rules would come by Thursday - when people find out which tier their local area will be in - or potentially before then.
'No Christmas truce'
It comes after the prime minister confirmed tougher tier curbs once England's lockdown ends.
Gyms and non-essential shops in all parts of England will be allowed to reopen from 2 December under a strengthened three-tiered system.
Areas will not find out which tier they are in until Thursday - and the decision will be based on a number of factors including case numbers, the reproduction rate - or R number - and pressure on local NHS services.
At a Downing Street news conference on Monday to outline a "Covid-19 winter plan", Mr Johnson admitted Christmas this year would be very different to normal.
"I can't say that Christmas will be normal this year, but in a period of adversity time spent with loved ones is even more precious for people of all faiths and none," he said.
"We all want some kind of Christmas; we need it; we certainly feel we deserve it.
"But this virus obviously is not going to grant a Christmas truce… and families will need to make a careful judgement about the risks of visiting elderly relatives."
Meanwhile, Mr Shapps announced people arriving in England from many countries will be soon able to reduce their quarantine period by more than half if they pay for a coronavirus test after five days.
The rules will come into force from 15 December and the tests from private firms will cost between £65 and £120.
Elsewhere, Health Secretary Matt Hancock told MPs the UK's new mass testing capacity could be used after the pandemic to diagnose a wider range of illnesses.
He said a British culture of "soldiering on" and going to work despite having symptoms of illnesses, including flu, "should change".
"In fact, I want to have a change in the British way of doing things where 'if in doubt, get a test' doesn't just refer to coronavirus, but refers to any illness you might have," he said.
Latest figures from the Office for National Statistics showed the total number of deaths occurring in the UK is nearly a fifth above normal levels.
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