Aer Lingus has cancelled all flights tomorrow because of threatened strike action by IMPACT cabin crew members.
Some 200 flights and 20,000 passengers will be affected.
The company is expected to lose £2 million in revenue.
About a third of cabin crew are still members of SIPTU, which has referred its claim to the Labour Court and told members to work normally. However, the company said last night it was impossible to plan arrangements for a minority of flights in the present uncertain situation.
It is also an indication that the company fears other Aer Lingus staff may not pass cabin crew pickets. Meanwhile, disruption by baggage handlers is expected to increase today and caterers are to resume their industrial action. This will cause continuing delays to flights and shortages of hot meals.
The Aer Lingus director of Group Change and Restructuring, Mr John Behan, has denied IMPACT claims that the strike is going ahead because the company will not enter substantive pay negotiations. "We have already offered to cut two points off the bottom of the scale in talks at the Labour Relations Commission with SIPTU, an increase of £1,400 for new entrants," he said.
"If that's not showing good faith, I don't know what is. We wanted to discuss pay and it was given to IMPACT in writing and a time-frame within which it was to be completed. And we were prepared for third-party assistance when and where necessary, but it has to be in line with the outcome of the Irish Congress of Trade Unions dispute committee [in regard to cabin crew]."
Mr Behan said that IMPACT negotiators had concentrated on trying to win company acceptance of its interpretation of the ICTU ruling in the dispute with SIPTU over who should represent cabin crew. He said the company was available to enter talks on pay "immediately".
An IMPACT spokesman described Mr Behan's reference to the inter-union dispute as a "red herring". It was Aer Lingus which was dragging other issues into the dispute.
"The company has not felt able to start talks on pay, pensions or casual contracts. Unless it is prepared to talk on these issues the strike will go ahead. The ICTU disputes committee is a red herring. We don't want the company to be involved in policing the ICTU disputes committee finding. That's an issue for IMPACT, SIPTU and the disputes committee."
SIPTU's Aer Lingus branch secretary, Mr Tony Walsh, said that if his members were laid off as a result of the strike he would be seeking compensation for them.
The Labour Relations Commission has informed both sides that it is available for talks. IMPACT has indicated that this would be its preferred option but the company says referral of the dispute to the LRC at this stage is premature.
IMPACT is also in dispute with Ryanair over pilots' rosters.