Aer Lingus passengers have been warned of possible flight cancellations after pilots served the carrier with notice of industrial action.
The airline said services could be affected from next Tuesday, when pilots based in Dublin and Cork will refuse to fly on days off and will arrive for work an hour later then rostered times.
Some 87% of members of the Irish Airline Pilots’ Association (Ialpa)/Impact trade union voted in favour of the industrial action.
Christoph Mueller, Aer Lingus chief executive officer, 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 June 7 unless Ialpa/Impact stand down their action.”
Aer Lingus was forced to cancel dozens of flights when cabin crew staged a three-week strike at the beginning of the year.
It maintained talks have been ongoing for some time to develop new manpower planning and roster models that will enable the carrier to achieve already agreed levels of productivity while providing pilots with better-quality rosters.
Aer Lingus said issues were exacerbated in recent weeks by a shortage of pilots due to higher than expected levels of staff turnover in the UK.
“In recent days, the company has invited Ialpa/Impact to talks and is willing to work towards a mutually workable solution to this issue,” it stated.
“Should this action proceed, it will have a significant adverse effect on profitability, occurring as it does in the peak summer season.
“Aer Lingus sincerely regrets the uncertainty this threat of industrial action by Ialpa/Impact causes its customers.
“However, the airline is using its best endeavours to reach a resolution.”
The former state carrier recently hinted its controversial €97m cost-cutting plan may not be enough to secure the future of the airline.
It blamed fuel costs, the economy, the cabin crew strike and the late Easter break for contributing to an operating loss of almost €56m in the first three months of the year.
The Greenfield programme planned more than 650 voluntary redundancies, pay cuts and a pay freeze.
A spokesman for Ialpa/Impact said the dispute centres on a shortage of pilots in Aer Lingus.
He maintained rosters were chaotic last summer, with pilots regularly forced to work six out of seven days throughout the high season.
“This issue has been raised consistently with management in the interim, but nothing had happened,” he added.
“The ballot was taken in anticipation of the same thing happening again and to put pressure on management.”
He said management and pilot representatives are due to enter talks this week.
“There has been an exchange of correspondence between Aer Lingus and the Ialpa branch of the union,” he added.
“Both parties are willing to enter discussions to see how this matter can be resolved.”