Pilots at Aer Arann are to take strike action next week after an overwhelming majority voted in favour of action in a dispute over pay cuts.
In a ballot on industrial action this afternoon by trade union IALPA, 91% of pilots voted in favour of strike action.
A spokesperson for Aer Arann has said the pilots' union is in breach of an agreement made last July, in which it gave a commitment that there would be no industrial action for 20 months.
A spokesperson for trade union IMPACT said pilots would strike on Tuesday, Wednesday, Saturday and Sunday of next week.
Aer Arann pilots took a 10% pay cut in 2009 and accepted the implementation of a pay freeze.
They are now calling for those cuts to be reversed.
IALPA served strike notice on Aer Arann in July last year, but withdrew the threat of industrial action after the company agreed to enter a process to address their concerns.
An agreement was reached to establish a tribunal to deal with pay-related issues.
That tribunal met for several days in June and July, but the union was not satisfied with some of the terms proposed by management.
It is understood Aer Arann has been attempting to postpone pay rises.
It said there will be no increase in pay for pilots this year, with the possibility of a pay rise in 2014 and another review in October 2014.