RACO has said the ‘free labour aspect of military service’ needs to end.
Members of the Defence Forces will be trained to provide aviation security duties at Dublin Airport.
Cabinet approved the move today and they will be available on stand by to assist the DAA.
In a statement, Minister for Defence Simon Coveney says he agreed to the request on a clear assurance this is a distinct piece of work, provided in extreme circumstances.
It will last no-more than six weeks and the support will be stood down in August when the busy holiday period has passed.
Minister Coveney has said the DAA has given assurances that they will continue with their own recruitment and additional security staff.
RACO has said this is in contrast to previous statements by Minister for Defence Simon Coveney TD and An Taoiseach Mícheál Martin TD which categorically ruled out the deployment of the Army, and confirmed that it was a human resources issue for DAA to solve.
RACO General Secretary Conor King commented: “Once again the Defence Forces are turned to in the country’s time of need, and will undoubtedly step up as the State’s insurance policy.
"We are concerned however that this is another example of the Defence Forces being used as emergency cover to compensate for management decisions in other state bodies.
"We must not ignore the recommendation of the Commission on the Defence Forces to end the ‘free labour aspect of military service’, which would be a further blow to morale in the organisation," he said.
"We need clarity on the type of roles our members will be expected to perform, what their working conditions will be, and what compensation they will be receiving for their work.
“We must ensure that our personnel are fairly treated, and adequately compensated for their work. Another concern is what essential training, career development or activities are being cancelled to facilitate this new task?
"We are already struggling to fulfill our existing roles due to a failure to retain personnel," he added.

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