Prison officers say there could be an outbreak of violence, or a murder, due to overcrowding in jails.
The number of inmates behind bars has increased by over 200 over the past year and now stands at 4,001.
That compares with less than 3,800 this time last year.
The Prison Officers Association will raise the issue at their annual conference in Sligo today.
General secretary John Clinton says it can't be blamed on more court activity after the Covid pandemic;
"We know that when you have overcrowding it leads to violence, as we said its competition for limited resources. We've been down this road before, we've had very serious situations in prisons where we've had overcrowding in the past and we really don't want to go back there again"
He says prisoners have been murdered in jail in the past.
