AER Lingus is planning to make timetable changes and merge flights in an effort to prevent disruption to passengers during a two-hour work stoppage at the country's busiest airport.
Company sources said it had activated its disruptions plan, adding it might consider hiring planes if necessary.
Up to 2,000 airline passengers face the prospect of being stranded next Monday after trade union SIPTU said it intended to mount industrial action at Dublin Airport in an ongoing row over the company's pension crisis.
The strike is planned between 10am and 12pm and would mostly affect transatlantic passengers.
The long-running row centres on a €750m hole in the Irish Airlines Superannuation Scheme, which covers workers in the airline and the Dublin Airport Authority.
The company pledged to make a contribution to plug the gap in return for increased productivity from workers, but SIPTU said the company had a €900m cash pile and workers had already given enough.
Last week employers' group IBEC and the Irish Congress of Trade Unions (ICTU) issued a five-point plan to resolve the row.
In a statement, Aer Lingus said there was a need for "cost-stabilisation" measures, and that it regretted SIPTU's stance: "Aer Lingus finds it most regrettable that SIPTU has taken this decision to use Aer Lingus customers as leverage in a dispute, for which a way forward is clearly available."
Sources said SIPTU workers were mostly employed in ground-handling including baggage and check-in, and that pilots and cabin crew were not affected.
Other unions including IMPACT, Unite, TEEU and the craft group of unions have not served strike notice.
Aer Lingus carries up to 25,000 customers a day, and sources said 2,000 would be affected. The strike notice would also affect bookings.
"You're looking at about 2,000 people being affected," one said. The 10am to 12pm period is a wave of transatlantic departures, and long-haul. It appears this is aimed at North America. The real risk in these situations is people just avoid booking. Once there's a cloud raised over a period, people just avoid booking on those days." "
SIPTU organiser Dermot O'Loughlin said SIPTU is seeking clarification from ICTU and IBEC on aspects of their mediation proposal and would not be withdrawing the strike notice until such time as it gets "acceptable clarifications".
"Our members are seeking the removal of pre-conditions introduced by Aer Lingus and which we believe to be unrelated to the pension crisis.
"Separately the union needs to establish if the Dublin Airport Authority is committed to the ICTU/IBEC proposals including the intention to refer certain issues to the Labour Court, where necessary," he added.
Brian Gormley, regional officer for Unite, said a collective decision will have to be taken by the unions before the industrial action can be called off.
He said the decision does not necessarily have to be unanimous so long as it is collective, and his union will take part in the stoppage unless the group of unions calls it off.
Impact, the largest union at Aer Lingus, has already said it is ready to attend discussions as laid out by IBEC and ICTU.