Scotland's first minister has said she "agonised" over whether to allow people to meet up at Christmas and would rather they chose not to.
A UK-wide deal was agreed on Tuesday to permit people to meet up in "bubbles" for five days over the festive period.
But Nicola Sturgeon said the "default advice" and "safest position" was still that people should avoid contact.
She said she would not be meeting her parents, saying she did not want to put them at risk "for the sake of one day".
Groups of up to three households will be allowed to form expanded bubbles from 23 to 27 December, but Ms Sturgeon said this was the "outer limit", adding that "the virus will not have gone away by Christmas".
The UK-wide plans were announced on Tuesday to lift travel restrictions across the four nations and allow people to visit close friends and relatives.
However, at her coronavirus briefing on Wednesday, Ms Sturgeon urged people to only use the extra flexibility if they really needed to - and suggested the rules were changed because ministers knew people would break them.
She said: "We agonise over all these decisions, and are trying to come to the outcome that balances best all these competing factors and desires people have.
"On this occasion we are trying to reflect the reality that for some people, sticking rigidly to the current rules over Christmas - if that means leaving loved ones on their own - is something people might not be prepared to do.
"Rather than leave everyone to navigate that themselves and decide their own boundaries, we decided to try and set some outer limits and boundaries to ask people to work within.
"That decision does not mean we are positively encouraging people to get together - I want to stress that just because we are allowing people to create a bubble doesn't mean you have to do it."
Ms Sturgeon added: "I will continue to ask you to err on the side of caution. If you have been making painful sacrifices for eight months to keep your loved ones safe, then think about whether you want to take a risk with their safety at the eleventh hour in this journey."
The first minister said she was "desperate" to see her own mum and dad, but said "I don't want to put my parents at risk for the sake of one day".
Some advisors have suggested allowing greater socialising over the festive period will cause a spike of new cases in January, with one government science advisor, Prof Andrew Hayward, telling the BBC that it would be like "throwing fuel on the Covid fire".
And Scottish government advisor Devi Sridhar told Channel Four News that "we are going to pay for Christmas holidays with probably a January national lockdown".
Opposition parties have pressed for the publication of any government risk assessments or modelling of the number of new infections or deaths which may result from increased mixing.
'Big scary model'
The Scottish Greens said "the last thing we need is to be sending out mixed signals", with MSP Alison Johnstone saying "parliament and the people of Scotland deserve to know how many extra infections the Scottish government is comfortable with".
However Ms Sturgeon and her National Clinical Director Prof Jason Leitch suggested this modelling does not exist.
Prof Leitch said there was not "very specific modelling" charting the number of potential cases, simply noting that "if we mix households we will get more infections".
And the first minister said there was no "some magic model or piece of analysis" which would answer hard questions for the government.
She said she would "really rather" people not travel and meet up if they can avoid it, saying that "if there was a big scary model I could put in front of you I wouldn't be deliberately hiding it".