Out-going junior Minister Willie Penrose has said a "comprehensive spending review" indicated there would be no economic benefit to closing the Columb Army Barracks in Mullingar.
"I'm on reasonably solid ground (in my) totally different view" to Justice Minister Alan Shatter's belief that the barracks should close on economic grounds, he said.
Deputy Penrose resigned from cabinet today over the issue.
The Taoiseach Enda Kenny said the savings would be in the order of €5m, and that the closure would release personnel for operational duties "of fundamental importance to the Army".
He added the proceeds of the sale of the barracks would be used to fund defence equipment and infrastructure.