If, as is expected, the members vote in favour of striking, it could ground hundreds of thousands of passengers over the busy Christmas period.
However, while notice of any action is likely to be lodged almost immediately, it could be delayed if the union chooses to fight the plans under collective redundancy legislation.
Yesterday the airline published the redundancy terms it was willing to offer staff who do not want to be transferred to the outsourcing company.
The terms mirror those offered when the airline sought job cuts in 2004.
Employees can choose from three redundancy options depending on their length of service.
nA lump sum based on company service — €7,000 per completed year of service with a minimum €40,000 and a maximum of €70,000.
nNine weeks’ basic pay per year of service to a maximum of 145 weeks.
nFour weeks’ basic pay per completed year of service to a maximum of 104 weeks plus a service bonus of €2,750 per completed year of company service to a maximum service bonus of €40,000.
Staff aged 55 or over with a minimum of five years’ pensionable service can retire immediately.
Staff have until December 15 to accept the offer.
Over the coming days, Aer Lingus will outline the financial details specific to each member of staff in writing and will open a helpline on November 13.
Announcing the offer, chief executive Dermot Mannion and chief financial officer Sean Coyle outlined its difficulties.
Mr Mannion said that while fuel costs had improved consumer demand had significantly declined.
“It is true Aer Lingus is in a strong balance-sheet position, but we need to conserve our cash for the future. These are difficult days. Doing nothing is not an option.”
Mr Coyle said the airline would next week publish an interim financial statement that would confirm losses for this year will exceed €20 million.
However, SIPTU national industrial secretary Gerry McCormack said: “Aer Lingus has once again attempted to bypass normal negotiating procedures by imposing redundancy terms unilaterally on employees. We have advised our members not to respond to this attempt to pressurise them into accepting redundancy.”