Deputy First Minister John Swinney today said the current level three restrictions in greater Glasgow and Lanarkshire are "not doing enough to suppress the virus" as the critical winter period approaches.
There are now concerns that intensive care capacity in some areas could be reaching its limit as the second wave in Scotland remains “stubbornly high”.
Any hotspot areas moved up to level four, which would mean bars, restaurants and non-essential shops all closing down again, would have to remain there for a pro-longed period to ensure cases start to fall, Mr Swinney said at the daily coronavirus briefing.
"I can confirm that officials of the Scottish Government have been in touch with a number of local authorities in the west of Scotland about the possibility of the areas having to be increased from level 3 to level 4,” he said.
"Those are in Greater Glasgow and Clyde and Lanarkshire health boards areas.
"We're obviously monitoring a number of other local authorities around the country that have been contacted because we are seeing in some circumstances quite significant increases in the prevalence of the virus."
Mr Swinney spoke out as 1,357 new cases were reported in Scotland today, an increase of more than 100 on Thursday. There were also 56 new deaths, which is up by 11, while hospital cases also rose by 21 to 1228.
First Minister Nicola Sturgeon will announce the next weekly review of the five-tiered system of Covid restrictions across Scotland on Tuesday.
But the Scottish Government has been making it clear that although cases have stabilised in many hotpots, they are not falling at the rate required. It means a move to the strictest level four - which has yet to be applied in Scotland - looks increasing likely.
Further discussions are planned with councils and incident management will also look at the data for these areas over the weekend before a final decision is reached.
The lag between catching the virus and being admitted to intensive a care a few weeks down the line could jeopardise hospital resources.
"We could find ourselves in a situation where cases could be falling but ICU (intensive care unit) capacity could be congested with a projection because of high levels of the virus in preceding weeks that that ICU capacity could be under real strain," Mr Swinney said.
The Central Belt has been under special restrictions for several weeks before the existing level three restrictions came into force almost a fortnight ago.
Although cases have plateaued, Mr Swinney admitted they remain at a “stubbornly high” level.
"We would like to see those numbers coming down more aggressively,” he said.
"That’s not been the case with level three restrictions, which is why we’re having to give consideration as to whether the level three restrictions give us enough of a supportive and effective set of arrangements to try to reduce the prevalence of the virus.
"That’s the active consideration that’s going on over the weekend to determine whether or not any of these level three areas should go up to level four because of the need to take more dramatic action."