Aer Lingus flights from Dublin, Cork and Shannon airports are facing disruption on Saturday because of an escalating row over the airline's restructuring plan.
A decision to hold general meetings of members at the three airports was announced yesterday by SIPTU, which represents more than half the airline's 4,000 staff.
It said the meetings would take place from noon on Saturday unless the company's chief executive, Mr Willie Walsh, lifted the September 14th deadline for acceptance of a redundancy package aimed at reducing staff numbers by a third.
Mr Walsh, however, indicated last night that the earliest he could meet a delegation from the union would be next Monday.
Unless that position changes today or tomorrow, the general meetings are expected to go ahead, causing delays to some flights.
Mr Michael Halpenny, a senior official with the union, said details of the meetings had not yet been finalised, so it was not yet possible to say how long they would last.
But he said it would be "reasonably accurate" to assume they would cause some disruption.
SIPTU members have already balloted in favour of industrial action, but strike notice has not been served on the company at this stage.
It is understood that any disruption on Saturday would be likely to take the form of flight delays rather than cancellations.
The decision to hold the meetings was taken at a meeting of SIPTU stewards, at which "resolute" opposition to the company's restructuring plan was expressed, said Mr Halpenny.
Aer Lingus wants to cut 1,325 jobs across most areas of the company and has offered an €80 million redundancy package, including up to nine weeks of pay per year of service.
SIPTU claims, however, that the terms are not as attractive as the headline figures make them appear.
It points out, for example, that a limit of 15 years of service is to be applied, while part-time and seasonal work is not to be taken into account in calculating payments.
It is also concerned about the impact on staff remaining at the company after the job cuts have been implemented.
Following yesterday's meeting of shop stewards, Mr Halpenny said it was a "perfectly reasonable request" that the September 14th deadline be put back to allow time for "proper negotiations".
He said the company was attempting to hold "gun-to-the-head negotiations at a time when even management agrees there is no immediate crisis or threat to the national carrier. On the contrary, it is on target for a €100 million profit this year".
Mr Halpenny told The Irish Times that Mr Walsh had offered to meet him last night on a "one-to-one" basis, but the SIPTU official insisted a full meeting take place with shop stewards present.
This had been unacceptable to Mr Walsh, who said he could be available for such a meeting on Monday, but not before.