The Scottish cabinet will meet later to consider further measures to help tackle coronavirus, as 2,464 new cases are reported.
The Scottish Parliament will then be recalled for First Minister Nicola Sturgeon to make an "urgent statement".
Ms Sturgeon said the "rapid increase in Covid cases driven by the new variant" was of "very serious concern".
"We are in a race between this faster spreading strain of Covid and the vaccination programme," she tweeted.
She warned on Friday that the next few weeks could be the most dangerous period for Scotland since March in the fight against Covid.
The latest government figures for coronavirus cases showed that 15.2% of Saturday's 17,328 tests were positive.
It is higher than the 2,137 cases reported on Friday, but still lower than Thursday's 2,539 positive results.
Figures for hospital admissions and deaths over the holiday weekend will not be published until Tuesday.
The cabinet is likely to consider a further delay to the return of Scottish schools and restrictions that are closer to the stay-at-home lockdown in March.
"All decisions just now are tough, with tough impacts," Ms Sturgeon wrote on twitter. "Vaccines give us way out, but this new strain makes the period between now and then the most dangerous since start of pandemic."
The Scottish government's emergency resilience committee heard on Saturday that "quick and decisive action is needed" as the new variant of the virus is becoming the dominant one in Scotland.
A Scottish government spokesperson said: "The even steeper rises and severe pressure on the NHS that is being experienced in some other parts of the UK is a sign of what may lie ahead in Scotland if we do not take all possible steps now to slow the spread of the virus, while the vaccination programme progresses.
"The strong message remains - people should stay at home as much as possible and avoid non-essential interaction with others."
This is just the fifth time the Scottish Parliament has been recalled and the second time within the last week.
Public health expert Prof Linda Bauld, from the University of Edinburgh, has said Scotland should be prepared for Covid restrictions to be extended as infection rates continue to rise.
She said there were no signs yet that the infection rate was levelling off, having risen suddenly from a daily rate of fewer than 1,000 to more than 2,000 per day in recent days.
She told BBC Scotland: "It definitely is a fragile situation and you can see that we have more cases than we would expect at the current time.
"We may be starting to see some of the impacts of the Christmas mixing, but also we know around four in 10 cases, from recent data, are of the new variant.
"I would imagine that the new variant is playing a role in these higher rates of infection and if these numbers continue to sit at where they are we are going to have more people in hospital in a week or two's time, and that is very worrying."
The new year offers new hope in the struggle against coronavirus with two vaccines now authorised for UK use - but it looks as if the situation will get worse before it gets better.
Ministers are worried by the rapid spread of the new strain of coronavirus during a holiday period when the highest level of restrictions are already in place.
They think more needs to be done to suppress the virus, to give the vaccination programme a chance to accelerate and give increasing numbers of people protection.
When the Scottish cabinet meets they are likely to consider tightening the current restrictions to something closer to the stay at home lockdown of March 2020.
That will almost certainly mean a further delay to the return of schools into February.
Ministers will take decisions on Monday morning with First Minister Nicola Sturgeon expected to make a statement at Holyrood in the afternoon.
Daily confirmed cases in Scotland reached record highs on the last three days of 2020, rising to to 2,622 on Thursday.
Ms Sturgeon warned last week there might be changes to the plans for reopening schools. Children start online learning from 11 January and are set to return to class by 18 January.
The education recovery group will meet on Monday.
'Step-change in testing'
Scottish Conservative leader Douglas Ross said the situation was "deteriorating and fast-moving" but any decision to extend school closures should be clearly explained to parents and teachers.
He said: "We have been here before so if schools remain closed, the Scottish government must show that it has learned from past mistakes in order to minimise disruption to education."
Scottish Greens co-leader Patrick Harvie said the Scottish government should prioritise teachers and school staff as vaccines were rolled out.
He added: "We must be honest and accept that most pupils, teachers and support staff cannot go back to schools until the situation is brought under control."
Scottish Labour leader Richard Leonard called for ministers to publish the evidence behind all of its decisions to ensure public consent and compliance.
"What is clear is that we need to see an acceleration of the vaccine rollout and a step-change in testing," he said.
"It is also clear that financial support from government has simply not been nearly sufficient to make up for the damage that lockdown measures have done to jobs, livelihoods and businesses. The SNP government must distribute additional funds to the frontline now."
Scottish Liberal Democrat leader Willie Rennie said: "With tighter restrictions on movement and in schools comes a greater responsibility on the government to show its workings.
"If we are to restrict people's movement then we need to see what the benefit will be. We need an exit plan to give people hope, as well as to show them what is required to ease the restrictions on our freedoms."