Nicola Sturgeon has warned of even greater lockdown restrictions including making "stay at home" guidance into law in a bid to contain the new mutant version of coronavirus.

The First Minister said the strain is spreading much faster and the Scottish Government will need to look at whether level 4 restrictions are sufficient.

Governments across the UK scaled back plans to ease the restrictions during Christmas due to the new covid variant which is believed to be 70% more infectious than previous strains.

In Scotland, the First Minister announced level 4, which is effectively lockdown, would be imposed from Boxing Day onwards for three weeks.

This includes the near total shutdown of hospitality.

Speaking at Holyrood, she referred to data which showed the prevalence of the new strain may be higher than previously thought.

She referred to testing analysis on a random sample of people in Scotland, which looked for a proxy marker known as the 'S-Gene dropout'.

She said: "There is continuing technical work underway on the use of the S-Gene dropout as a marker for the new strain and it is not absolutely definitive that every case with this marker will be the new variant.

"However, this analysis suggests that in the week beginning December 9 around 14% of positive cases in Scotland already had this S-Gene dropout. This compares to just 5% at the end of November."

She added: "It is not unreasonable to assume that the proportion may be higher by now. And Public Health Scotland is carrying out further analysis.

"Now 14% is, of course, still a significantly lower level than England, where it is thought that the new variant already accounts for 36% of cases, and maybe even higher in London and the south-east.

"However, the very rapid spread in London and the south-east serves as a warning of what we could face here if we do not take firm action to suppress the virus. We have a real concern that, without significant counter measures, we could be facing another period of exponential growth as we enter the new year."

As a result, she said the Government could tighten level 4 further.

She added: "As more evidence of the impact of this new strain becomes available, we will consider whether there is a need to strengthen level 4 restrictions any further."

She said that the virus is spreading "much faster" now than in March, saying: "We need to consider whether the current level 4 restrictions will be sufficient to suppress it."

She added: "For those living in level 4 areas - which from Saturday will be the vast majority of us - our strong advice is to stay as local as possible and at home as much as possible.

"We will be considering in the days ahead whether we need to place that advice in law."