The Psychiatric Nurses Association is warning of further closures to beds and wards in the country's hospitals today.
Its members are refusing to work overtime as part of their dispute with the HSE over compensation for nurses who are attacked at work.
Des Kavanagh from the PNA says he expects whole wards to close over the coming days because of the dispute.
On Saturday the overtime ban forced the closure of beds in Tallaght General and St Vincent's Hospitals in Dublin; and Naas General Hospital in Co Kildare.