Ambulance personnel belonging to the Psychiatric Nurses Association are to escalate their campaign of industrial action over union representation rights by staging a 24-hour strike next month.

However, the date of the extended stoppage by paramedics, advanced paramedics and Emergency Medical Technicians will not be announced until the union's conference on 2 May.

The PNA has already mounted six 12-hour strikes this year in a dispute over the HSE's refusal to recognise the union's right to represent members in their National Ambulance Service Representative Association branch (NASRA).

However, despite multiple strikes, which required the deployment of Defence Forces ambulance crews to plug gaps in service, the dispute remains deadlocked.

Traditionally, SIPTU was the main union representing around 1,800 frontline ambulance personnel, but since 2010 some have defected to NASRA.

The PNA/NASRA now claims to represent around 500 ambulance personnel, though SIPTU disputes that figure.

The HSE has so far refused to recognise the PNA, arguing that recognising another union would lead to fragmentation and impair good industrial relations.

It has also ceased collecting and remitting union subscriptions through the payroll system for PNA members.

The PNA has accused the HSE of trying to force them to be members of unions they do not want to join.

General Secretary Peter Hughes noted that the NASRA branch had successfully represented members since 2010.

He accused the HSE of arbitrarily deciding that because growing numbers of ambulance personnel were joining the PNA ambulance branch that it would simply refuse to engage with it or allow the branch to continue to represent these frontline health workers.

He said no union could allow its members to be treated in this way by an employer.

The PNA noted that contingency plans for ambulance cover would be put in place, with Defence Forces personnel expected to provide back-up support again.