The Health Service Executive has warned that tomorrow's indefinite overtime ban by psychiatric nurses will have a very significant impact on vulnerable patients in acute and community mental health facilities across the country.

It has also confirmed that last year, it spent over €16 million on agency nurses, and €15.78 million on nursing overtime, to plug gaps in staffing.

HSE National Director of Community Operations David Walsh said that in order to ensure that safe services are maintained in acute units during the overtime ban, it will be necessary to cancel many community services designed to support people to live at home.

As a result, many of those people may not receive their usual service and may have to attend their local acute unit instead.

He noted that the overtime ban would apply in both community and acute units, adding that for that reason the HSE was trying to concentrate resources on keeping those acute units safely staffed.

However, he stated: "There will be instances where that is not possible".

Mr Walsh said the HSE recognises that there is a very significant problem regarding reliance on overtime in mental health services - but hopes the proposed new enhanced nursing agreement will help to make careers in mental health more attractive.

Asked how long mental health services could sustain an overtime ban, Mr Walsh said that on the first day there will be implications for services, which was not a sustainable position for the HSE to be in.

The HSE said that during 2018, there were 12,106 admissions to acute inpatient beds in mental health services, but was unable at the moment to supply an accurate figure for the total number of patients being supported by the service in the community sector.

Local crisis management teams in the HSE community healthcare organisations are reviewing the situation on a service by service basis regarding contingency measures.

The HSE said it welcomed the fact that child and adolescent mental health services will not be affected by the dispute, but urged the PNA to agree to a referral to the Labour Court to resolve outstanding issues. 

PNA General Secretary Peter Hughes said it was disappointing that psychiatric nurses found themselves having to take industrial action. 

He said members were resolute that mental health services could not continue under a cloud of constant staff shortages, with 700 current vacancies and a "haemorrhage" of staff to better paid posts in the private sector and abroad. 

He said yesterday's talks at the Workplace Relations Commission had shown "once again" the lack of any urgency by the employer to agree detailed terms to end the dispute.

Irish Patients Association spokesperson Stephen McMahon voiced concerns about the potential impact on vulnerable patients.

He noted that psychiatric nurses played a very important role in protecting people from themselves, particularly where they may display self-harm or cause harm to others where the necessary supports are not available.

He urged both sides to get back to the negotiating table to avoid putting the most vulnerable patients at risk.