The lifting of the eviction ban is a "horror movie" for tenants who have received notices to quit.
That's according to Fr Peter McVerry, who was speaking as the ban on no-fault evictions is set to be lifted at midnight.
Protests are planned over the weekend to highlight the potentially disastrous impact of the move on thousands of people in the rental sector.
Fr McVerry, founder of the Peter McVerry Trust, told Newstalk Breakfast people affected are at a loss.
"I'm extremely concerned," he said.
"I think this is a horror movie for all those tenants who have received notice to quit.
"They're totally at a loss as to what to do.
"There is virtually no emergency homeless accommodation available anywhere in the country.
"Normally families would be put up in hotels, but as we know hotels are full and many hotels are reverting back to tourism.
"I am absolutely horrified at what is going to happen over the next few months".
Fr McVerry said while some landlords may want to sell, they could have been exempt from the ban - rather than scrapping it entirely.
"The inconvenience to the vast majority of landlords who want to sell their property... of waiting, perhaps, another 12 months is minor compared to the trauma that is now going to be inflicted on thousands of households," he said.
"I am horrified, I think it's an appalling decision.
"I think the decision was made to prevent this happening in the early months of next year, when local and European elections are pending".
Fr McVerry said nobody supports this move by he Government.
"There is not one single homeless charity that supports the ending of the eviction ban," he said.
"Every single charity has come out and said, 'This is a disaster'".
'I feel hopeless'
Asked if there ever is a good time to lift the ban, Fr McVerry said: "No - there's no good time to lift the eviction ban.
"But during the eviction ban, it would have been hoped that measures would have been put in place to mitigate the worst effects of the eviction ban.
"If we had extended it for 12 months, we could put 7,000 modular units on-site in the next 12 months".
Fr McVerry was asked what advice he would give to tenants facing eviction.
"I don't have any advice to give them, I'm sorry - I feel hopeless, to be honest," he said.
"Of course go to your local council and look for emergency accommodation.
"If the local council doesn't have it, I don't know what you do to be honest: that's the nightmare scenario.
"They should certainly contact Threshold, because a number of those notices to quit were deemed invalid by Threshold," he added.
Listen back to the full interview below: