The cabinet agreed on Friday that hospitality venues, cinemas and theatres should have a closing time of 8pm from Monday to deal with the threat from the Covid-19 Omicron variant.
It is the second successive Christmas that the sector has faced restrictions at what is traditionally its busiest time of the year.
Danny Collins, the publican at the Boston Bar in Bantry, Cork said the decision could not have come at a worse time for the industry.
It is shocking to be quite honest, the staff don't know whether they are coming or going
He added: “I knew something was going to come along, but what they have done to us is just devastating, just before the height of our season.
“The Christmas trade covers a quiet January, February and March for us.
“It is shocking to be quite honest, the staff don’t know whether they are coming or going.
“We have staff on day shifts and nights shifts, that all has to be moved around. They are worrying whether they have jobs or not and there are a lot of decisions that we have to make now in the next couple of days.”
Mr Collins added: “You must take into account that lots of pubs don’t open until about 6pm in the evening, so the night trade has completely gone. It is devastating for those pubs that open late, devastating for the whole industry.
“There has to be help for us from the Government some people are on large mortgages.
“You can’t just think of the people who own the pubs, you must also think of the people who work in these businesses who have homes and families to look after, and they are facing up to a lot of uncertainty at the moment.
“It could not have hit at a worse time.
“Last year something similar happened, we were closed down totally last year. Then I didn’t reopen until mid-July.”
Carol Meenan, the co-owner of the Yellow Pepper Restaurant in Letterkenny, said the measures were devastating.
“It is very difficult; imagine you are trying to fit one sitting in whenever your main restaurant operation is usually from 7:30pm on, that is when you start to have the bulk of your customers who are having the main evening dinner menu.
“It is very difficult earlier in the evening to attract people in.”
She added: “This week and the week after Christmas are among our best weeks of the year and that gets you through January and February and into March.
“In a restaurant you can do social distancing well. People sit at their tables and we can manage on tables of six no problem.
“We can manage with the large Christmas parties being cancelled because we could fill it with smaller groups and people were coming out to support us.
I can't imagine in January how viable it would be to open with having to close the doors at 8pm
“But now, you just can’t manage. We are going to have to have a meeting with our staff and see what we can do.
“Our diary is quite heavily booked for tables after half-seven for the next couple of weeks and I don’t know what we are going to do with all of them, obviously we can’t push everybody back into earlier sittings.
“It is devastating for everybody.”
Carol said the Government needed to introduce a support package for the sector.
“Hopefully that will come very quickly.
“We will open our doors this week, our diary is well booked for now.
“But I can’t imagine in January how viable it would be to open with having to close the doors at 8pm. I don’t know how that is going to work.”