Aer Lingus cabin crew have voted in favour of industrial action over a row concerning rosters.
97% of IMPACT members backed the ballot for industrial action, up to and including strike action if the airline fails to agree to implement a revised roster.
The airline could face rolling work stoppages during the busy summer period starting as early as later this month.
"The cabin crew branch committee will meet with our divisional executives in coming days the coming day to discuss the nature of the industrial action," said Niall Shanahan, from the IMPACT trade union.
"What we have today is a decision by cabin crew members on a ballot for industrial action, up to and including strike action- if the airline fails to agree the implementation of a revised roster … and acceptable time-off arrangement after long-haul flights."