Workers at the company have been balloted on industrial action and it is expected that when the results are revealed later this week, they will show a significant majority in favour of action.

Industry sources have indicated that Siptu, the union that represents the airline workers, has already drawn up a detailed programme of disruption.

It is understood that the union, which is concerned about the conditions of the airline workers' transfer, has given up on its hopes of having talks with the company at the Labour Relations Commission (LRC) after apparent mixed signals from the airline.

Aer Arann chief executive Garry Cullen wrote to the LRC on Thursday stating that, while the airline did not recognise unions, it would be willing to enter talks facilitated by the LRC's advisory service, which specialises in dealing with disputes where there is no recognised union.

Union sources have claimed, however, that when subsequently contacted by the LRC, Cullen refused to enter into talks unless the airline was allowed to proceed with its outsourcing plan, a move which is understood to have infuriated workers at the airline.

"It was a disingenuous offer which has only served to harden attitudes and has greatly increased the likelihood of serious disruption, " said one informed source.

A spokeswoman for Aer Arann declined to comment on whether Cullen had set any preconditions for talks.

"Aer Arann is operating under the recommendations of the LRC's advisory service, " she said. "We do not anticipate any disruption whatsoever to services."

The LRC was unavailable for comment at the time of going to press.