Ryanair could potentially face a compensation bill of up to €44 million if the 170 victimisation claims taken by its Dublin-based pilots were to be upheld by a rights commissioner. The first of these cases is expected to be heard in mid-June.

The complaints, some of which have been lodged by the airline's most senior pilots, stem from Ryanair's action in seeking to persuade the pilots to accept terms and conditions attached to their training to fly its new fleet of aircraft.

The initial complaints were first submitted by the airline's eight most senior captains to the Labour Relations Commission last November. Many of the pilots have made multiple complaints.

In the past week, fresh victimisation claims have been made on grounds of the airline's refusal to give the pilots a pay rise. Ryanair said on Tuesday that it had awarded a 3 per cent pay increase to its staff with the exception of its pilots.

It said that the increase, backdated to April 1st, had been granted following "direct negotiations" with its staff last month.

It claimed that the pay rise was awarded to staff who negotiated directly with the company. The pilots are members of the Irish Air Line Pilots Association (Ialpa), which is part of trade union Impact. Ryanair claimed it withheld their pay increase because they had chosen not to negotiate with the airline.

The victimisation claims will be heard by a rights commissioner who has the powers to award a maximum settlement equal to twice the complainant's salary where a claim is upheld.

Ryanair has claimed that its team of pilots are among the highest paid in the airline industry and earn up to €130,000 a year.

Each of the pilots could stand to win compensation of up to €260,000 if successful.

Sources among the pilots suggest that up to 70 further victimisation complaints may yet be taken.

The Labour Court is to investigate a case taken by the Ialpa on behalf of some Ryanair pilots relating to their terms and conditions of employment.

The investigation will centre on the pilots' right to training by the airline, their contracts and rights where redundancies are sought.

The Labour Court findings are binding.

Ryanair is claiming that the new Industrial Relations (Miscellaneous Provisions) Act 2004 cannot be used to enforce trade union recognition against an employer, such as Ryanair, which does not engage in negotiations with trade unions.

The Labour Court accepted this submission but noted that the legislation does provide a measure of protection to employees when pay and conditions are not freely determined by collective bargaining.

Capt John Goss, the pilot who secured an injunction restraining Ryanair from conducting disciplinary proceedings against him pending a full court challenge, was among the group of the airline's eight most senior pilots to lodge the first victimisation claim.

The airline is also fighting a number of separate legal challenges related to its ongoing dispute with its pilots.

These include High Court proceedings it has taken against Ialpa accusing it of conducting an "organised campaign of harassment and intimidation of Ryanair pilots" through a website set up last year for its pilots.

Ryanair has claimed the website, www.repaweb.org, had been a conduit for intimidation of pilots considering flying the airline's new Boeing 737-800 series aircraft to be based in Dublin later this year.

"In addition to threatening and intimidating Ryanair pilots, this website has also published specific threats ... which have been the source of a formal complaint to the Garda Síochána," it said.