Some members of the Defence Forces are sleeping in cars because of poor pay and conditions, Fianna Fáil leader Micheál Martin has claimed.
He accused the Government in the Dáil on Wednesday of having “its collective head in the sands’’ about the crisis.
It existed at all ranks and levels, he said.
"At some point, someone has to say this is unacceptable,'' Mr Martin added.
He said there was a crisis in morale, pay and conditions, retaining members generally, health and safety.
He said researchers in the University of Limerick interviewed more than 600 personnel revealing "a shocking story of neglect of the Defence Forces which underpinned democracy".
Mr Martin said some officers had told how they were kept awake at night by concerns about whether work carried out on aircraft in the Air Corps left them safe for flying because so many experienced personnel had left.
Taoiseach Leo Varadkar said while he did not accept there was a deep crisis in the Defence Forces, there were substantive issues.
He said the Government strongly supported the Defence Forces.
A “very successful” recruitment of 800 people was under way and the budget had been increased for next year, he said.
Mr Varadkar said there was a difficulty in recruiting people in certain areas, particularly in the Air Corps, because of higher pay levels in the private sector.