THREE different households will be allowed to form a Christmas "bubble" and mix for five days over the festive season, in a UK-wide plan agreed by ministers and the devolved nations.

The “cautious and limited relaxation of the rules” will also allow people to travel between local authorities and across the UK between December 23 and 27. 

First Minister Nicola Sturgeon urged Scots to consider carefully whether the opportunity to mix for a few days is necessary given the risk of spreading the virus.

She admitted that even this short relaxation would "give the virus a chance to spread". 

She said:“We know that for some, contact with friends and family is crucial during this time as isolation and loneliness can hit people especially hard over the Christmas period. The 'bubble' approach aims to reduce this impact.

“But we must be clear, there cannot be any further relaxation of measures for Hogmanay.  Even this short relaxation will give the virus a chance to spread. Our priority is to suppress transmission of COVID-19 and reduce the risk to the vulnerable and those who have spent so long shielding - and that involves abiding by the rules.

“Just because you can mix with others indoors over this time, that doesn’t mean you have to. If you choose to stick with the rules as they are, then you will be continuing the hard work to beat this virus and prevent its spread.”

Under the new guidance, people will be allowed to form an exclusive “bubble” between three households. 

Those bubbles should remain in the one area and should, as a bubble, follow the travel advice for the level they are in.

These bubbles can gather in a home, an outdoor place or a place of worship. In all other settings, like a pub, those who have formed a bubble must only socialise with members of their own household

Households deciding to form a bubble will be urged to limit social contact before and after the period of relaxation

Earlier, in the day Ms Sturgeon urged Scots “to err on the side of caution”.

She said: “Our overall advice will be for people to use any flexibility carefully and only if they believe it right and necessary for their personal circumstances.” 

The Scottish Greens demanded that evidence is published to set out how much progress in suppressing the virus could deteriorate if rules are relaxed at Christmas.

Co-leader and health spokesperson, Alison Johnstone. said: “We all very much understand that any loosening of restrictions over Christmas is a trade-off.

"Will the First Minister ensure that the Scottish Government publishes the evidence base behind the arrangements, and can she ensure that that includes modelling of the impact that the arrangements will have on the number of new infections over the Christmas period?

"For example, what level of increase in infection will be considered acceptable?”

Sturgeon said the government would continue to “publish evidence and modelling, as we think that that is helpful and appropriate.”

She added: “There is an important point about being candid with people. I think that, across the UK, we all recognise that this will be difficult but important to communicate.

We are seeking to give people the option, should their personal circumstances require it, of a bit of flexibility over Christmas, whether that is providing a window of time or some flexibility in the number of households that can come together. 

“What we are absolutely not doing is encouraging everybody to go out and use that to the maximum. This is about people continuing to make judgments.

“I would say to anybody who thinks that they can get through the Christmas period without mixing more than we are advising right now that they should do that.”