Prison officers said they were disappointed last night over talks with the Irish Prison Service following the recent spate of violence at Dublin's Mountjoy jail.
The Prison Officers' Association (POA) said it was voicing concerns about the safety of staff and inmates at the country's jails, and it called for the reopening of the Curragh Prison in Co Kildare and Spike Island prison in Cork to deal with overcrowding problems.
After five-hours of talks, John Clinton from the POA said: "A very difficult meeting . . . and the difficulty mainly was principally around the issue that there was no acceptance from the official side that there was overcrowding in the prison service.
"We have the opposite approach to this, that there is a difficulty."
Mr Clinton said prison officers had been highlighting this issue for a number of years.
Brian Purcell, director of the Irish Prison Service, said the numbers of inmates in Mountjoy would be kept to acceptable levels that management feel they can deal with.
The talks followed the killing of inmate Gary Douch at the prison, and two other separate stabbings.