Aer Rianta workers are to ballot for strike action in response to plans by the Minister for Transport, Mr Brennan, to restructure the company.
SIPTU, which represents about 80 per cent of the company's 1,900 staff, is to begin balloting members next week, while similar action is planned by other unions. Industrial action is threatened if Mr Brennan proceeds with plans to remove control of Cork and Shannon airports from Aer Rianta, and have them managed by new boards.
SIPTU also plans to act if the Minister moves to privatise or part-privatise the company, or to sell off any of its assets.
Members, about 1,000 of whom work at Dublin Airport, will be balloted separately on the two issues and asked to support industrial action up to and including "a full withdrawal of labour". Mr Dermot O'Loughlin, of the union's civil aviation branch, said a parallel protest campaign would also be held if the Government sanctioned the building of a new, independent terminal at Dublin Airport.
A panel set up to advise the Government on this is due to report shortly. Mr O'Loughlin said such a move would dilute the terms and conditions of Aer Rianta workers.
Unions, he said, were prepared to discuss Mr Brennan's plans but there was a "strong feeling on the ground that we will resist any attempts to restructure without consultation". The SIPTU ballot is expected to be concluded within a fortnight.