The public has been given a two-week deadline to curb the rising spread of Covid-19 or risk plunging the country into another dark period dealing with the virus.
The stark warning was delivered yesterday as public health doctors told people to stop socialising so freely, wear masks in the gym if they cannot physically distance and to not go on holiday abroad, despite a green list of "safe" countries to be published next week.
"We are in a position of high uncertainty at the moment," said Professor Philip Nolan of Maynooth University, who is tracking the virus.
"We know the R number is above one. We don't know how far above one and it could be as high as 1.8.
"The best estimate is that it is around 1.4."
He said the country is still seeing very low numbers of new cases but what we do over the next week or two will make the difference.
It could be the difference between 20 to 30 daily cases or 150 or 170 cases a day over the coming month.
The situation is quite "precarious" for the next couple of weeks on how the disease will track.
"The opportunity is here now to bring the disease back under control," Professor Nolan said. "We have an opportunity now to maintain suppression of the virus."
He was speaking as another death from Covid-19 brought the toll to 1,749.
Another 21 confirmed cases of the virus were confirmed.
"The cases which we will report next week have already been seeded," Dr Ronan Glynn, Acting Chief Medical Officer said.
"However we have the power to limit the spread and impact of this disease beyond that.
"The way we do so is through following public health advice, avoiding high-risk situations and encouraging our friends and family to do the same."
Meanwhile, Greece and Cyprus may be among the European sun destinations in next week's "green list" of countries where Irish holidaymakers can enjoy quarantine-free holidays.
It means that Irish tourists returning home will not have to restrict their movements for two weeks as a precaution in case they pick up Covid-19 abroad. The list is expected to be quite limited and will exclude many holiday destination favourites.
However, the finalisation of the list will go down to the wire and not be signed off until Monday's Cabinet meeting because a few days of virus flare-ups can dramatically change a country's rate of virus per 100,000.
Ireland's prevalence is now nearly 4 per 100,000, which has deteriorated in recent weeks and the aim is to find countries which either on par or better than us, that Irish holidaymakers can safely travel to.
The UK, France and Italy are not expected to be on the list and Dr Glynn said that the National Public Health Emergency Team (NPHET) - which is advising against foreign travel - has not seen it.
He said that he accepted the NPHET recommendation to avoid going abroad, while at the same time publishing a green list, gave a mixed message.
"From a public health perspective, if a country has a disease rate more or less the same as here and people take all the precautions they need to take, getting there and while they are there, getting back and when they come back, then you can't say there is an additional risk.
"But the vast majority of countries people in Ireland would want to go to for non-essential travel do not have a similar epidemiological profile to ourselves and we have been very clear that people should not go to those countries," said Dr Glynn.