The threat of industrial action at Aer Lingus and the Dublin Airport Authority has increased after unions decided to mount a coordinated campaign to oppose proposed cuts in their pension benefits.
SIPTU is the only union in the affected companies that has so far balloted to take strike action.
However, at a meeting this afternoon, representatives of all other unions decided to commence consultation and balloting for industrial action.
ICTU Industrial Officer Liam Berney, who is coordinating the union response to the row, said members had reacted with horror and frustration to the trustees' proposals to cut benefits.
He said that in practical terms, unions that have not yet balloted members will now consult with them and commence that process.
Mr Berney said the unions intend to coordinate any industrial action on a specific date not yet fixed.
He said if the dispute was not resolved, there was a real prospect of Aer Lingus and the airports at Dublin, Cork and Shannon shutting down simultaneously.
Mr Berney said that at this point neither employer had indicated that they were prepared to put more money on the table, and industrial action was a real prospect unless that changed.
Earlier, SIPTU Pensions Policy Advisor Dermot O'Loughlin said he expected SIPTU to serve strike notice next Wednesday, and that industrial action could take place over the St Patrick's Day period.
Aer Lingus has threatened to take legal action to prevent SIPTU from taking industrial action.
In a letter to the union's Pensions Policy Advisor Dermot O'Loughlin, Aer Lingus Director of Change and Engagement Sean Murphy queries the fact that SIPTU restricted its strike ballot to members of the IASS pension scheme, but did not ballot members who were in other pension schemes.
Mr Murphy states: "Aer Lingus must reserve its right to take all steps, including legal action, that may be necessry to prevent such actions proceeding in a manner that may cause irreparable loss and damage to Aer Lingus and which would make the resolution of the pension issue more difficult."