Dublin is facing three weeks of new Covid-19 restrictions, which would cut off the capital from the rest of the country.
The National Public Health Emergency Team (Nphet) is expected to recommend enforcing Level 3 restrictions across the entire county, which will cause further economic damage to the national economy.
Under Level 3, people will be banned from leaving the county for non-essential journeys.
People living in other counties will be prohibited from entering Dublin unless it is for work, education or another essential purpose.
People living in Dublin will be asked to work from home.
Places of worship will be asked to move their services online, while funerals and weddings will be limited to 25 people. Museums, galleries and other cultural attractions will be closed.
In a clear indication that the Government plans to act quickly, an emergency meeting of the Cabinet Committee on Covid-19 has been scheduled for tomorrow morning to consider Nphet's recommendations before the weekend.
It can also be revealed that Higher Education Minister Simon Harris sought assurances at the last Cabinet meeting that the Government will act sooner on public health advice than it did on Nphet recommendations on Dublin.
"Harris asked for an assurance that if Nphet made a recommendation, it would be made quickly so we don't have a situation like the last week," a source said.
"We have lost five days in the fight against the virus because they didn't move and he's really not happy about it."
The source said it is "inexcusable to not act" on public health advice and insisted "speed trumps perfection" when fighting the virus.
Details of Nphet's recommendations emerged yesterday after the Department of Health published the letter that Health Minister Stephen Donnelly received last Thursday.
The group urged the minister to encourage people living in Dublin not to leave the county unless it was necessary and, if they do, to only meet one other household.
They also said home visits should be limited to one other household of no more than six people.
They sought limits on the number of people who can attend sporting events and said people should be asked to work from home if they could.
In a stark warning, Nphet said there is "no guarantee that further measures may not be necessary in the coming days or weeks".
The letter signed by acting chief medical officer Dr Ronan Glynn also warned "there is a limited time period in which to act" as international evidence shows increases in new cases are followed by a rise in deaths.
"While the recommended enhanced measures have the potential to arrest the trajectory of the disease, there is also a very real potential that the situation could deteriorate further," Dr Glynn said.
While the recommendations were received by the Government last week, they were only announced on Tuesday and came into force yesterday.
A senior Cabinet member defended the delay in reacting to the advice by noting that the rise in cases has yet to lead to a significant increase in hospitalisations or deaths.
"Yes, there is an increase, but bear in mind during an average flu season there are hundreds of deaths and we don't got into lockdown," the source said.
Nphet is due to meet at 10am this morning to discuss the increasing number of new coronavirus cases in Dublin and elsewhere in the country.
The expert health group's recommendations will then be reviewed by the Covid-19 Oversight Group chaired by Department of the Taoiseach secretary general Martin Fraser.
Mr Fraser and Nphet's recommendations will then be forwarded to the Cabinet Committee on Covid-19, which will meet tomorrow morning.
A incorporeal Cabinet meeting may be organised later that afternoon if a decision is taken to introduce new rules for the capital before the weekend.
The prospect of restrictions being introduced in Dublin on a regional basis rather than county-wide was not ruled out yesterday by senior figures in the Government.
However, it is unlikely to be the approach on this occasion.
There is also a belief it will be difficult to impose restrictions in individual areas of Dublin because the public would not be clear on where boundaries lie.