Aer Lingus has warned that extensive cost-cutting measures will have to be implemented across the airline.
Aer Lingus planes at Dublin airport
Chief executive Dermot Mannion told staff representatives of the company's 3,500 employees at a meeting last night that major job cuts would have to be taken regardless of Ryanair's €1.48 billion bid for the airline.
The job cuts are expected to be introduced in areas such as maintenance, catering and the carrier's US operations.
The staff representatives were told that a "root-and-branch" review was being immediately instigated.
Michael Halpenny of Siptu
It is understood Mr Mannion told the meeting that staff were facing a stark choice - face cuts under the current Aer Lingus management team or under Michael O'Leary's Ryanair.
Mr O'Leary has confirmed that if he gains control of Aer Lingus he will reduce the workforce. Media reports have suggested that up to 1,000 jobs may be cut from the airline.
Michael Halpenny of Siptu said this morning he had not been informed of the management plan prior to its announcement last night.
Speaking on RTÉ Radio, Mr Halpenny said it was reasonable to expect that any such plans would be discussed with union management before being released generally. He said he hoped to speak to Mr Mannion this morning, ahead of a meeting with Aer Lingus management later to seek clarification.
"We met with the company a couple of weeks ago against the backdrop of recent events and they confirmed to us they fully intended to honour all agreements.
"We have commitments from the company - indeed, signed off by the chairman of the company - and we would expect the company to honour those."