The Irish Prison Service has said it has no control over the number of prisoners as it was revealed that almost 200 inmates are without beds due to overcrowding.
There are currently 4,583 prisoners in the State's jails, with the system at 104 per cent capacity.
It means 194 prisoners are sleeping on mattresses on the floor, four times the number at the start of the year. Almost half of these (85) are in Dublin's Mountjoy Prison.
This has led to concerns for the safety of both prisoners and staff.
In a statement, the Prison Service said it has to accept all prisoners sent by the courts and it has no control over the numbers of inmates committed to custody.
It said the prison system is subject to peaks and troughs and it is working with the Department of Justice to ensure a safe environment.
