The Prison Officers Association is raising concerns about overcrowding in the country's jails.
Around 50 inmates have been sleeping on mattresses on the floor this week, according to the organisation.
There are 550 more people in the country's 14 jails now than a year ago.
This time last year. the figure was 3,767 - but it now stands at 4,317.
The current total is 94 beds short of capacity.
However, both the female and male jails in Dublin's Mountjoy and Limerick prisons have exceeded their capacity.
Karl Dalton, the general secretary of the Prison Officers Association, says some inmates are sleeping on floors.
The Irish Prison Service says it must accept all inmates committed by the court - and can't refuse any.
It says jails are particularly high when courts are at their busiest.
