6,000 psychiatric nurses across the country will begin industrial action this evening.
The Psychiatric Nurses' Association says its members will work only their contracted hours because of health management's failure to address a recruitment and retention crisis.
The PNA says the overtime ban will continue until the issue is resolved.
The HSE says it's putting measures in place to manage the situation, but has warned they may have to reduce the availability of services in the community, in order to maintain services in acute psychiatric units.
HSE spokesman, David Walsh, is calling on the PNA to take part in talks at the Labour Court in an effort to resolve the dispute: