Aer Lingus pilots have served notice of industrial action to the airline from next Tuesday.
87% of its members voted in favour of industrial action when balloted.
The Irish Airline Pilots' Association and IMPACT have served notice that from next Tuesday 7 June, pilots based in Cork and Dublin will not work on rostered free days or annual leave days.
They will also report for duty one hour later than their rostered report times.
Criticising the notice of action, Aer Lingus CEO Christoph Mueller said: ‘This withdrawal of flexibility will destroy our ability to operate a proper schedule as we will miss our airport slot times, parking stands, gate positions and will be unable to fulfil flight connections for customers.
‘In addition pilot and cabin crew operational duties will be out of sync which may result in cabin crew having insufficient hours to operate all flights.
‘This may lead to a full cancellation of operations from Tuesday 7 June unless IALPA / IMPACT stand down their action.’
The Labour Relations Commission has invited both sides to talks to resolve the dispute.
Aer Lingus has accepted the invitation.