Cabin crew at Aer Lingus have voted in favour of industrial action.
The union Impact said members have voted in favour of taking action up to and including a strike.
Impact wants the airline to agree a revised work roster for short-haul flights with acceptable time off after long-haul flights.
The vote was passed with 97% in favour. A union official said the result of the ballot showed how strongly the cabin crews felt about the issues, the BBC reported.
Cabin crew are seeking a roster of five days at work and three days rest. The roster already applies to the company’s pilots.
Impact said cabin crew members could work for up to 60 hours over seven days. This meant shift patterns of six days on duty, one rest day and then another six days working.
Members of the union’s cabin crew branch are due to meet soon to discuss industrial action options.