Ambulance workers with the Psychiatric Nurses Association are to escalate their industrial action.
Over 500 members of the PNA are involved in a row with management over union recognition.
The personnel involved - including paramedics, advanced paramedics and emergency medical technicians - want the HSE to recognise the union of their choice.
They've already held six days of strike action, during which they downed tools from 7am to 5pm
However, they are now planning a series of 24 hour strikes.
Dates for the strikes will be announced next month.
Members of the union confirmed their plans to escalate their action following a meeting in Mullingar today.
General secretary Peter Hughes said they want to send a message to the HSE that members' resolve is 'undiminished'.
He said: "Once again in the face of the HSE’s effort to force over 500 PNA ambulance branch members [...] to give up their right to be members, and be represented by their trade union, our members must escalate their industrial action to secure a fundamental right available to workers throughout the country.
"‘As this dispute moves to a more serious and disruptive level of industrial action it is time for politicians of all parties to demand that the HSE account for its actions in instigating a completely unnecessary dispute."
The HSE has previously stated that they already recognise a number of unions for ambulance workers.
Officials claim recognising further organisations will not be good for industrial relations.