Ambulance workers from the Psychiatric Nurses Association say they've been left with no choice but to go on strike.
500 of them have begun a 24 hour walkout across the country as part of a dispute over union recognition.
The workers will still deal with emergencies and the HSE says all calls are being responded to.
Bertie Dowling is an advanced paramedic in Mayo and he told Midwest News that there has been no movement in this dispute.
“It’s just about Union recognition, we just want our union to represent us,” said Mr Dowling.
“They won’t even tell us the reasons why they won’t talk to us.”