Talks between Aer Lingus unions and management have adjourned at the Labour Relations Commission without reaching an agreement.
The five unions representing workers at the airline have gone away to consider the company's final proposal, while Aer Lingus is to examine the cost savings achieved from the talks.
The Aer Lingus board is to meet this evening to review progress on its plan to shed 676 jobs and cut pay as part of its €97m a year cost reduction programme.
LRC Chief Executive Kieran Mulvey said the overnight negotiations were extremely tough.