A decision on a "short, sharp" national lockdown across Wales is due to be announced later.
First Minister Mark Drakeford is set to make an announcement about a two or three-week "firebreak" around midday.
The Welsh Government cabinet is meeting this morning to make a final decision over the circuit-breaker, after considering advice from experts.
But mounting speculation about a two-week lockdown to slow down the virus has been fuelled by a letter.
Wales director of the Confederation of Passenger Transport, John Pockett, wrote to members on Friday, saying a lockdown would start at 18:00 on 23 October and end on 9 November, which would "take us back to the situation in March".
He subsequently told PA Media he was "surmising" the outcome.
The Welsh Government's cabinet met on Sunday afternoon, with further discussions taking place on Monday morning before a final decision is made.
On Friday Mr Drakeford said a "firebreak" lockdown would be a "short, sharp shock to all our lives".
The Welsh Government Cabinet is meeting now to make a final decision on a ‘fire break’ to control the spread of the virus in Wales.— Mark Drakeford (@fmwales) October 19, 2020
I will announce further details in my press conference at 12:15.
You can watch this live on @WelshGovernment pic.twitter.com/TesK9H9Cie
"We would all have to stay at home to once again save lives. But this time it would be for weeks not months," he said.
It comes as talks continue to discuss if Greater Manchester will move into England's top tier of Covid rules.
In Wales, the extent of the expected national lockdown is currently unclear as talks continue to discuss whether or not schools will close and what financial support the Welsh Government can give to businesses when the furlough scheme comes to an end next week.
It comes as half-term is due to start on Monday 26 October, but it is not clear if a lockdown will coincide with that.
The Welsh Government has been urged to consider a four-week shutdown - or even longer - to turn around the surge in coronavirus cases, that has been almost a thousand daily cases for three of the last five days.
"In the first week of a circuit-breaker, you would still see cases probably going up because there would be people who caught it before the measures came in," Jamie Jenkins, former head of health analysis at the Office for National Statistics, told BBC Radio Wales.
"You might be looking at at least two and a half weeks before you see any improvement, and then if you're looking a the data, you'll probably want to see the rate coming down to the rate we saw about a month ago.
"You're probably looking at two, three, four weeks - and then having to say we have to go a bit further - that is the difficulty of putting a time limit on a circuit-break when you are trying to assess how long this is going to be."
Currently about 2.3 million people in Wales are living in communities under local lockdown rules - 15 of Wales' 22 counties plus Bangor and Llanelli - where coronavirus infection rates are at their highest.
Restrictions include a ban on travelling outside of those areas without "reasonable excuse", the ending of extended households or bubbles and people can only meet other households outdoors.
Latest figures showed 16,982 people tested positive for the virus in the UK on Sunday, with almost a thousand in Wales.
Businesses across Wales said they were anxious to find out whether they would be told to close.
Welsh hospitality bosses warned a Wales-wide temporary lockdown could put jobs at risk for almost a third of their 140,000-strong workforce, as well as the 40,000 employed in their supply chain.
"It's going to be a really difficult time and I can see a lot of business going to the wall," David Chapman, executive director in Wales of industry body UK Hospitality, told BBC Radio Wales.
"I can see jobs being shed as furlough is coming to an end. We need full support, if we don't get support now we are going to lose people in large numbers.
"We could lose up to 40,000 jobs which will be a massive impact in many rural and coastal communities.
"When we were shut down in March, the government came up with a package which was brilliant and immediate. The business rates and furlough package was great - but things are starting to get tighter.
"If we don't get the furlough equivalent or more, we're going to have to balance cutting jobs, which will damage the community, or shutting businesses which would be even worse.
"But if we can help, stay open and get through to next summer we can start contributing the £37bn a year we put into the UK economy."
A circuit-breaker is a tight set of restrictions imposed for a fixed period of time and the Welsh Government has said its "firebreak" version would mean restrictions lasting "for weeks not months".
Councils agree "something needs to be done" to stop the surge in coronavirus cases in Wales but the leader of the group representing councils says ministers will decide "the best option" as they "balance health and the economy".
"We are seeing cases rising, almost a thousand on Sunday and the impact on the economy is quite substantial right now," Andrew Morgan, leader of Rhondda Cynon Taf council and the Welsh Local Government Association, told BBC Radio Wales.
"Not only does every one of those cases have to self-isolate right now but all of their close contacts have to - so every day contact tracers are asking thousands of people to self-isolate.
"Over a 10-day period we are talking tens of thousands of people so if you think there is no harm to the economy right now it is foolhardy - and these numbers will continue to grow."
Mr Morgan, who has been part of talks with government, said financial support to Welsh businesses will be "fundamental" to plans of ministers as "businesses are anxious to know" the new measures.
Mr Drakeford previously said that a "successful firebreak would re-set the virus at a lower level".
"Together with a new national set of rules for the whole of Wales after the firebreak period we would have slowed the virus down enough to get us through to Christmas," the first minister said.
The Welsh Conservatives have called for an emergency Senedd debate as this is "where major announcements of this kind should be made" in a "parliamentary democracy".
"I think it's unacceptable, I think the first minister needs to make a statement in the Senedd, and that's why we've called for an emergency session," said Darren Millar, vice-chair of the Welsh Conservatives and Clwyd West MS.
"If they want growing consensus then they also need to engage with other political parties and they haven't been doing that."
Plaid Cymru said the case for a firebreak was "now overwhelming" and urged the Welsh Government "to address the weaknesses of the test, trace and isolate system".
"I want as few restrictions as possible to be imposed, but properly enforced, and with clear support for people and businesses affected," said Plaid's health spokesperson Rhun ap Iorwerth MS.
Plaid's proposals include measures to "improve our track, trace and isolate system, to safeguard workplaces, and to ensure sufficient financial support for businesses and their employees".