Fear of gang violence and a shortage of prison officers are being blamed for a dwindling number of inmates at Mountjoy Prison in Dublin taking up education.
Latest figures show just one in six inmates at the Dublin prison availing of classes at times during the year, a fraction of the uptake in other jails.
Minister for Justice Charlie Flanagan said the drop-off in prison education is "linked directly" to the rising numbers in solitary confinement.
Entire wings at Dublin’s main prison have been put under a protection regime.
The jail has the lowest ratio of education uptake among all facilities in the State’s penal system.
The new figures show the percentage of prisoners taking classes at Mountjoy dipped to as low as under 17 per cent during the year.
“The drop in numbers participating in education is linked directly to the increasing number of prisoners on protection and the fact that by April all prisoners on both A and B wing were on protection,” said Mr Flanagan.
Earlier this year, a prison visiting committee found up to a quarter of inmates at Mountjoy are on solitary confinement at any given time. The watchdog attributed the high level of prisoners under protection to fears of being attacked by gang members.
In an attempt to resolve the issue, prison managment overhauled the class timetable so as to segregate classes for those under protection and those who are not.
Prisoners in solitary confinement take classes in the afternoon while everyone else attends in the morning.
But Mr Flanagan has admitted the changes have resulted in a “notable reduction” in overall participation levels as “many protection prisoners are unwilling to mix freely with each other”.
Wheatfield Prison, in Clondalkin, west Dublin, also has comparatively low uptake of education among inmates. The percentage of prisoners taking classes has varied between 15 per cent and 27 per cent during the year.
Mr Flanagan blamed officer shortages and the snow earlier in the year for the cancellation of many classes.
Wheatfield has a dedicated prison education centre, which also hosts extracurricular wellness and musical events, while a separate school operates on the segregated landing for prisoners under protection.
The number of prisoners taking education is as high as 80 per cent in Loughan House open prison in Co Cavan, or 70 per cent in Dublin’s Arbour Hill, which holds a high number of sex offenders and older inmates.
Almost two-thirds of prisoners take classes in the Dóchas women's prison at Mountjoy compared to about half at Portaloise, the maximum security jail for inmates convicted by the Special Criminal Court.
Between a quarter and a third of inmates avail of education at the Midlands and Castlerea prisons.
The Department of Education and Skills funds 220 teachers for prisons throughout the State.
Mr Flanagan said a recruitment campaign for new prison officers will “greatly reduce the number of occasions on which classes have to be suspended due to the unavailability of discipline staff”.