Its on a dispute over staff transfers and redundancy terms.
Forsa Trade Union's criticised Aer Lingus management over a decision not to attend a Labour Court hearing, due later this month, on the closure of the company's Shannon base.
The union had referred the issue to the court, after failing to reach agreement over staff transfers and redundancy terms.
83 cabin crew are affected by the move which was announced by the company in May.
In a statement, Aer Lingus says the decision to close the Shannon cabin crew base was not taken lightly and a reversal will not be possible.
Fórsa critical of Aer Lingus stance on Shannon base https://t.co/bguF0DE22G via @rte
— Fórsa trade union (@forsa_union_ie) July 8, 2021