Unions were yesterday preparing to pull back from the brink of an all-out confrontation with the Minister for Transport, Mr Brennan, over his planned break-up of Aer Rianta.
Sources in a number of unions said that alternative avenues, including talks with Mr Brennan, would be explored before industrial action was implemented.
Rank-and-file members, however, are understood to be pressing for a strong response to the Minister's decision to establish Dublin, Cork and Shannon airports as separate entities.
Workers claim the move will threaten the viability of the two smaller airports.
Officials and senior shop stewards in four Aer Rianta unions - SIPTU, the TEEU, IMPACT and MANDATE - meet on Monday to work out a strategy to oppose the Minister's plans.
Two of the unions, the TEEU and MANDATE, have already balloted for industrial action in the event of Mr Brennan breaking up Aer Rianta. The other two unions could decide to proceed with ballots of their own, but a more cautious approach is expected at this stage.
Later on Monday the vast majority of the 2,350 staff at the three airports are expected to attend meetings organised by SIPTU, beginning at 2 p.m.
While these have the potential to cause serious disruption, an Aer Rianta spokeswoman said it was advising intending passengers to turn up for flights as normal. "It's difficult to know how the meetings will affect operations, but we are working on a contingency plan to keep any disruption to a minimum."
Although both sides expressed a willingness yesterday to resume dialogue, no talks between Mr Brennan and the unions were planned.
A spokesman for the Minister said he had made it clear he was available to meet the unions at any time. "He has given a guarantee there will be no threat to jobs, no changes in the terms and conditions of those working at the airports, and much stronger representation for workers on the new boards being set up."
Exploring how such guarantees on pay and conditions, not only in Aer Rianta but also in CIÉ, can be made to work, is likely to be near the top of the agenda if Mr Brennan and the unions do start talking again.
SIPTU vice-president Mr Jack O'Connor said the belief among many union activists was that the guarantees on pay and conditions given by the Minister were just "meaningless media packaging".
Nothing specific had been put forward, he said, about how workers' pay, conditions and standards of employment would be guaranteed. "If that remains the case then we are left with no alternative but to either surrender what we spent half a century trying to achieve or to go out and fight for it," he said.
Mr Arthur Hall, regional secretary of the TEEU, said the unions' first response would be to try to pursue "some sort of dialogue" with the Government.
The next priority would be to try to convince the public and taxpayers of the "economic madness" of Mr Brennan's plans.
Industrial action, he said, would be implemented only as "a last resort".
The threat of disruption at the three airports on Monday was criticised by the Dublin City Business Association, which said it supported Mr Brennan's decision and accused Aer Rianta workers of "putting customers last".
The Chambers of Commerce of Ireland also backed the Minister's move and criticised SIPTU's "knee-jerk" reaction. Its chief executive, Mr John Dunne, said experience had shown that competition increased jobs and economic strength.
"SIPTU needs to grow up and realise that this move has the potential to be a fantastic opportunity rather than a threat, if the unions respond constructively."