Siptu shop stewards at Aer Lingus are to meet on Thursday to review the situation in light of a rejection by the union of a deal on the introduction of new work practices.
Aer Lingus is seeking to introduce new, more flexible work practices for some 1,800 staff, who mainly work in ground operations, which it says will save the airline about €10 million a year.
But union members voted three to one to reject a deal agreed by its representatives and management last month. The move has led to fears of further industrial action at the airline.
The proposed deal averted a possible strike in February which could have affected up to 20,000 passengers per day.
In a statement tonight, Siptu said will also be in contact with the company to ascertain its position. Yesterday National Industrial Secretary Gerry McCormack said: "The union has put a huge effort and resources into trying to secure agreement in the different local areas on cost cutting measures.
"However, the company's failure to produce workable rosters in line with the proposals has contributed significantly to the decision by our members to reject them," he said.
Under the plan, staff would have had to work shifts of varying lengths while the company will have the freedom to move personnel between duties, for example between check-in and boarding, in the course of a shift.
It is understood that about €7.5 million will be generated in savings at Dublin airport and €2.5 million in Shannon.