Overcrowding in Irish prisons is a "ticking time bomb", according to the Prison Officers Association.
Gabriel Keaveny, Deputy General Secretary of the POA, said the current levels of overcrowding in prisons have never been witnessed before.
Speaking on RTÉ's News at One, he said: "We have never seen the levels of overcrowding here before... It's very challenging for our members.
"The current situation of in or around 5,000 prisoners with 500 out on temporary release, it's unsustainable and we are saying that as prison officers."
He said the prison service has reached a situation where it has practically no other place to put prisoners and in the most modern prison in Cork, every cell there with the exception of a handful are doubled up and 50 prisoners are sleeping on the floor.
He said Castlerea prison in Co Roscommon is designed to hold 34 prisoners, but there are nearly 80 prisoners there, with ten on the floor and all cells doubled up.
'Recipe for disaster'
Mr Keaveny said the current situation of overcrowding is a recipe for disaster.
"The days and weeks ahead unfortunately does not bode well."
On the idea of transferring prisoners elsewhere, he said that as there is no place to transfer them to, that suggestion was like moving deckchairs on the Titanic.
He said his organisation had come up with suggestions, but all of the proposals were rejected by the prison service who came up with none themselves.
"The prison service are defunct of any ideas in relation to this. meanwhile our members at the cold face are dealing with chronic overcrowding in really challenging situations."
Mr Keaveny said that as the summer approaches and evenings get longer, if prisoners do not get access to services and are cooped up in cells all day, it is "hugely problematic for our members".
He called for emergency proposals to be put in place by the prison service.
"Any funding announced now is about three and five years away," he said.
Mr Keaveny added that the prison service is only coming up with a handful of spaces, which he said were of no use.
"The only alternatives they have is more prisoners on the floor, or let out prisoners."
Number in prisons up 11% in 2023
The Irish Prison Service has said the overall daily average number of prisoners in custody in 2023 was 4,583.
"This represents an 11% increase when compared to 2022, and 15.4% higher than the pre-Covid benchmark," the IPS said.
Earlier this week there were 4,940 people in prisons around the country, meaning the prison service is operating at 110% of overall capacity.
In a statement, the prison service said short-term projects are under way with "potential to deliver an additional 95 spaces in 2024", including at Castlerea, Loughan House, Limerick and Wheatfield.
Medium-term projects should provide a further 106 spaces: 78 in the Dóchas Centre and 28 in Castlerea, including six disabled-access cells.
Plans have also been outlined for four capital projects at Castlerea, Cloverhill, the Midlands and Mountjoy prisons which can accommodate up to 670 prisoners-construction "expected to start" on a phased basis in 2025 to 2027.
