An interim order restraining the Labour Court from proceeding today with a formal investigation into a row between Ryanair and a number of its pilots was secured by the airline yesterday afternoon.

The restraining order, granted by the Supreme Court, applies pending the outcome of Ryanair's appeal against a recent High Court finding that there is a trade dispute between Ryanair and the trade union, Impact, which represents the Irish Airline Pilots Association, and that the Labour Court has jurisdiction to investigate the dispute.

The proposed investigation is being conducted under new industrial relations legislation which, Ryanair claims, is being used by pilots to achieve compulsory trade union recognition through "the back door".

Yesterday, Ms Justice Susan Denham, presiding over the three-judge Supreme Court, said that if the Labour Court investigation proceeded today, and the Supreme Court later upheld Ryanair's appeal, the time and expense of the Labour Court and other possible court hearings would have been wasted. The delicate area of the relationship of employer and employee would also have been altered.

The restraining order did no more than allow the prospect of the Ryanair appeal being successful, and the interests of justice required such a restraint, she held.

The judge also agreed to a request from counsel for Impact to treat the hearing of the Ryanair appeal as a priority matter.

The dispute began in summer 2004 when Ryanair began the conversion of its Dublin fleet. This involved retraining for some 90 pilots, who were told they could either pay €15,000 for the training or sign a bond abandoning their entitlement to raise matters with the Labour Court.

In November 2004, the company said it would not negotiate with Impact but would negotiate directly with the pilots, who subsequently referred the matter to the Labour Court.

In January last, the Labour Court found that a trade dispute exists under the Industrial Relations Act, 2001, that it was not Ryanair's practice to engage in collective bargaining, and there was no operative internal dispute resolution procedure in place.

Ryanair argued it had traditionally operated non-union recognition and had an employee representative committee where matters were resolved. However, the High Court last month rejected Ryanair's challenge to the Labour Court's findings.

At the Supreme Court yesterday, Mr Martin Hayden SC, for Ryanair, said if the Labour Court investigation proceeded today, Ryanair would be unable to get off "a conveyor belt", which could ultimately lead to Circuit Court enforcement orders against the airline.

This was the first time the relevant legislation was before the courts and it created a situation where decisions of the Labour Court could be affirmed by the constitutional courts.

The legislation was all predicated on the Labour Court having the jurisdiction to investigate a trade dispute, an issue which should be determined by the Supreme Court before the Labour Court proceeded.

Mr Hayden said the legislation was intended to catch employers who did not engage in collective bargaining but Ryanair was not such an employer.

The airline had sent a letter to pilots last July and replies to that showed there was a collective agreement reached between Ryanair and its pilots in 2000. Some 30 pilots had gone through the training process so far.

Mr Gerard Durcan SC, for Impact, said Ryanair was trying to restrain an investigation by a statutory body in a situation where the High Court had found there was jurisdiction for that investigation.

The investigation was only the first stage in a three-stage process and the Ryanair application was premature.

The legislation made clear the legislature believed industrial disputes should be heard quickly, but this matter had been going on for more than a year and the pilots were not much further on.

The situation was "deeply unfair" and a number of senior pilots were served with redundancy notices last August.

The only "choice" given to them was to give up their claims, pay €15,000 or be made redundant.

At the same time, Impact could not process the pilots' claim before the Labour Court because of the Ryanair legal proceedings. Nor could it engage in industrial action, as this was precluded by law when matters had been referred to the Labour Court.

While some senior pilots were able to raise the €15,000 which preserved their right to go to the Labour Court, the same situation might not apply to junior pilots.