Behind-the-scenes moves to avert a strike by Aer Lingus pilots on February 11th have begun. It is possible that an independent mediator could be asked to chair talks between the two sides.

It is also understood that moves to intensify the search for an investor or buyer have been put on hold by the airline's board, which met yesterday.

A senior source said no further move could be made until the threat of industrial action had passed.

In addition, directors are said to be very conscious that the general election could be called soon, leaving little time for legislation to clear the way for outside investment.

Contacts between senior trade union leaders and Aer Lingus management may resume as early as today, but they face a tough challenge.

The pilots' union IMPACT yesterday served strike notice on the company, and warned that it would not defer industrial action unless compulsory redundancies for 10 junior co-pilots are withdrawn.

The company has so far refused to withdraw the notices and accused IMPACT of trying to change the agenda.

It points out that the strike ballot was in support of a demand that all pilots be treated "no less favourably than other members of the Aer Lingus workforce regarding terms of redundancy and early retirement".

The strike ballot was also held in defence of all existing agreements between IMPACT and the company.

On Wednesday, management agreed to extend the same terms to all pilots as all other employees after the previous package attracted only seven applications.

A spokesman for the airline said: "All pilots have now the exact same terms available as applied to all other work groups within the airline and the company is adhering to all agreements. The reasons given by IMPACT for balloting no longer exist."

With the issue of different redundancy terms removed, IMPACT had to address the problems in the airline's Survival Plan, or explain: "Why should pilots be the only group of workers to say no to change?"

IMPACT assistant general secretary Mr Michael Landers said, "Aer Lingus wants the public to think this is about pay or pilots' refusal to change. It is not.

"The reality is that pilots have so far contributed €9 million [£7.1 million\] to the airline's recovery by agreeing to forego an independent pay award until the airline is back on its feet."

Mr Landers said pilots are the only group of Aer Lingus staff to be issued with compulsory redundancy notices and have conditions attached to a voluntary redundancy offer.

When yesterday's ballot ended it was found that pilots voted by 475 to 14 for industrial action. The union is now treating this as a mandate to oppose compulsory redundancies.

On the plus side for Aer Lingus, a European Court of Justice official said in a legal opinion yesterday that bilateral agreements between member-states and the US were contrary to EU law.

The European Commission said it would seek modification of the agreements if the court confirmed that view in a ruling in the coming weeks.

Such a development could open the airline to majority ownership by a non-Irish entity.

This is prevented under terms of the current Ireland-US bilateral agreement, and blocks the possibility of selling a controlling stake in the company outside the Republic.

But an EU-wide agreement with the US could have serious implications for the "Shannon stopover". The current agreement demands that half of all flights between the Republic and the US stop at Shannon.