The SIPTU union has rejected what it has labelled as a "derisory" offer by Aer Lingus and the Dublin Airport Authority to resolve the €750m deficit in their staff pension funds.
A strike at Dublin, Cork and Shannon airports was narrowly avoided on Monday after unions and management agreed to resume talks.
According to SIPTU, Aer Lingus has offered to provide between €9-15m to resolve the pension crisis, while the DAA has agreed to provide up to €43m.
The trade union has now written to the Labour Relations Commission seeking its help over the issue.