SIPTU members employed as firefighters at Sligo Airport have commenced industrial action in a dispute over union recognition.
The work-to-rule action includes a ban on overtime, maintenance work, and other measures.
SIPTU has accused airport management of refusing to engage with the union for the purposes of collective bargaining.
Earlier this month, members voted overwhelmingly for industrial action, up to and including strike action.
SIPTU said the action that began today will slow airport operations.
"This action will not result in an immediate halt to the airport's operations, as our members will continue to provide crucial emergency services, but it will degrade its operation over time," said SIPTU Organiser Andrew Clune.
"All this can be resolved immediately by management respecting their employees' wishes to be professionally represented by their union for collective bargaining purposes," Mr Clune said.
SIPTU said support for rescue and medical flights will continue and fire prevention operations will be maintained throughout shifts at the airport to allow the emergency services to operate.
Sligo Airport has been contacted for comment.
