The Garda Representative Association has said says the policing system will fall apart if the Department of Justice goes ahead with plans to cut the Garda payroll provision by €35m this year.
Garda authorities will have to reduce officer numbers to 12,000 by December under the plan, from the current level of 13,400.
The Garda Commissioner Martin Calllinan has previously said he would not like to see Garda numbers to fall below 13,000.
President of the GRA John Parker said the cuts would have serious implications on policing in Ireland.
"The system that is already creaking at the seams would fall apart," he said.
"The specialist units - the units set up to tackle white-collar crime, the importation of drugs, the traffic corps units - a lot of those are being run down (already). They can't function without significant numbers."