Minister for Defence Alan Shatter has said it is absurd to suggest that there is an economic argument for keeping a full barracks open to cater for a Reserve unit that trains only once or twice a week.
However, PDFORRA, which represents enlisted personnel, said the decision to close army barracks should be reversed.
Mr Shatter was responding to Opposition criticism that it was wrong to be seeking space to rent for Reserve troops in Clonmel, Cavan, Mullingar and Castlebar when the barracks there are about to close.
The Minister confirmed that the four barracks will shut on 30 March.
He said the Reserve Defence Forces in each barracks will be provided with alternative rented accommodation prior to the closure of the barracks.
Mr Shatter said this is a normal arrangement for Reserve units in other locations around the country and consistent with how the previous Government dealt with the matter.
The Department has ten permanent rentals and 30 part-time rentals in place, including part-time use of parish and community halls, as well as some commercial premises.
The total annual cost is less than €100,000 for all 40 buildings.
Mr Shatter said: "It is simply absurd to contend that there is an economic argument for keeping a full barracks open to cater for a Reserve Unit that may only train for a few hours once or twice a week when alternative rented accommodation can be provided for a small fraction of the cost."
The Deputy General Secretary of PDFORRA, Simon Devereux, said the decision to close four barracks last November was flawed and should be immediately reversed.
Mr Devereux said the barracks at Clonmel, Mullingar, Cavan and Castlebar; all have a long and proud tradition of service to the State and engagement with their local communities.
He said the comments of Deputy Willie Penrose, who resigned as a Minister of State over this issue, should be revisited and reconsidered.
Fianna Fáil's defence spokesperson Dara Calleary said no money would be saved by the closures of the barracks.
Mr Calleary said they will not be able to sell the four barracks in the current climate and will have to pay maintenance and security costs on the facilities.
