However, the Garda Representative Association (GRA) last night described the clampdown as an extraordinary development and said it would affect the capacity of all gardaí on the frontline to do their job, particularly those involved in the investigation of crime gangs in the capital.
"The agreed overtime must now be reinstated if we are to keep our streets safe in the lead-up to Christmas," the GRA added.
At the moment, the force is spending around €9m during each roster. There are 13 rosters in the year.
The cuts are intended to bring roster spending down to €6.5m-€7m. This compares with about €8m in 2017.
Much of the overtime spending by specialist units against gangland crime was front-loaded this year for operational reasons and proved to be highly effective. As a result, these will not be affected as seriously as other units.
Meanwhile, farmers' representatives warned the scale of rural crime s being under-reported because of intimidation by criminal gangs.
Farmers under threat from intruders and burglars have been told to "stand by their brothers, stand by their neighbours … because they'll be there far quicker than the gardaí will".
The rallying call came from Seamus Sherlock of the ICSA during a debate on rural crime at the Irish Independent tent at the National Ploughing Championships.
Mr Sherlock added: "It's like a war zone out there … stand with your brother next door, stand with your neighbour. The neighbour will be there 10 times quicker than the Garda will."
He said that every county suffers from rural crime, and farmers on the fringes of Dublin were at risk because of the influence of city gangs seeping into the countryside: "Every meeting that I chair, rural crime will come up even if it's not on the agenda."
Mr Sherlock was joined by Laurence Ward, former IFA Dublin chairman, who warned that farmers often felt too intimidated to report intruders or crimes to the authorities.
"They (the intruders) will say, 'If you call the guards we'll burn down your hayshed, we'll open all the gates and let the animals out on the road," he said. "It is pure intimidation."
The debate was hosted by Irish Independent journalist Paul Williams who said that if faith in the police force wavered, farmers would be tempted to take matters into their own hands.
A show of hands among the audience demonstrated that all would support somebody who defended their land or their person with a legally-held firearm.
The debate was sparked by North Dublin farmer Patrick Walsh, who was viciously assaulted on his land by four men with lurcher dogs just weeks ago on All Ireland Sunday. Mr Walsh, who told his story to the Irish Independent last week, is recovering from a dislocated shoulder, four cracked ribs as well as cuts that required six stitches.
"There are 20 minutes of that evening I cannot recollect," he said. "When I woke up I was lying in the middle of the road.
"This didn't just happen last weekend, it's been happening for the last 20 years.
"In the last five or six years, there's been so much aggressiveness."
He said he still had faith in gardaí as the "law of the land" but criminals must be prosecuted. He cautioned against using firearms, "in case they're taken off you and used against you in the heat of the hunt".
Kerry-based solicitor Deirdre Flynn cautioned that the law on defending your person or property was ill-defined.
The law allowed a person to use "reasonable force" if they believed they were in danger or that a crime was about to be committed, she said: "But it doesn't define reasonable force."