The union representing Aer Lingus cabin crew has warned that weekend flights may be disrupted as a result of a dispute over pay and productivity.
Informal talks at the Labour Court aimed at solving the row ended around lunchtime without a resolution.
Labour Court Chairman Finbarr Flood said the parties had been unable to establish a basis to resolve the issues, but added that the court remained available to both parties if required.
In a statement, the union accused the company of seeking excessive changes in working conditions.
IMPACT claims the demands could mean predominantly female cabin crew working additional flights while losing meal breaks and money.
Passenger safety not at risk, says union
Under the work-to-rule, which was escalated yesterday, cabin crews are refusing to operate flights unless they have the agreed complement of staff as set out in the company's survival plan.
IMPACT warned that it would react strongly if staff were disciplined for sticking to agreed working conditions, and said the work-to-rule would show how much Aer Lingus relies on cabin crew flexibility and goodwill to maintain flight schedules.
The union stressed that passenger safety would not be at risk, and said cabin crew had voted by 97% to support the action.
A spokesperson for Aer Lingus said the company remained available for direct or informal talks on the basis of a commitment to ongoing change.
Meanwhile, the Aer Lingus schedule is operating normally, and provision has been made with tour operators in relation to weekend charter flights affected by the dispute.
