Aer Lingus Chief Executive Dermot Mannion

In a bizarre twist to the decision of Aer Lingus to open a base at Belfast International Airport, up to 500 pilots at the airline are to stage a 48-hour strike next Tuesday and Wednesday in protest at what they said were moves by the airline to employ pilots in Belfast on less favourable terms and conditions than those applying to staff in Dublin.

The pilots, who are also shareholders, are in effect claiming that the model that has brought prosperity to Ireland since the late 1950's is not acceptable to them.

About 87% of exports from Ireland, are made by foreign-owned firms, principally American, who operate in accordance with local market pay and conditions.

The Aer Lingus pilots, who are members of the Irish Airline Pilots' Association (Ialpa) branch of the trade union Impact, are reported to be considering further industrial action if the dispute is not resolved.

In a reaction last night, Aer Lingus said it was "angry and disappointed that pilots would choose to attack customers in an act of self-centred brinkmanship".

A spokesman said the recruitment of new staff at local rates had always been a fundamental element of the plan to establish new bases outside the Republic of Ireland.

The airline also warned that passengers were likely to face disruption to services next week and said management was working on alternative arrangements and contingencies.

Advertisements for pilots to be based in Belfast were placed on the Aer Lingus website on Monday. They did not set out the terms and conditions on offer.

Ialpa president Capt Evan Cullen is reported to have said after a meeting in Dublin on Monday that Aer Lingus was in flagrant breach of its collective agreements and of solemn commitments made by the airline to its employees in advance of last year's stock market flotation.

"We are not going to allow Aer Lingus treat its Belfast-based pilots as second-class citizens who can be paid less and treated worse than their colleagues in Dublin.

"Aer Lingus has freely entered into collective agreements that cover all pilots employed by the airline and we just want the company to honour its commitments," he said.

Aer Lingus said it had been in negotiations with pilots for some time on a range of efficiencies that were essential to maintain the competitiveness of the business.

"Earlier this year both the Labour Court and the related Flynn report recommended that the company be allowed open new bases outside the Republic of Ireland on local pay and conditions.

"In calling this strike action, the pilots are directly ignoring those recommendations. This cynical attempt to use a new base as a veto on essential progress towards competitiveness is unacceptable and is deeply regrettable given the need to grow the company as an independent force in the market," the airline said.