The Dublin Airport Authority (DAA) has been granted leave to seek a High Court injunction against Siptu's planned strike action at Dublin and Cork airports next Friday.
The DAA claimed it had no choice but to take legal action after the trade union declined to "respond positively" to two separate communications calling on it to lift the threat of industrial action.
Siptu is planning a four- hour work stoppage at the three airports from 5am to 9am on Friday next in advance of the busy St Patrick’s weekend.
The follows the breakdown of talks between Aer Lingus and union representatives aimed at resolving a dispute over workers' pensions.
In a statement, the DAA said it was seeking an injunction on the basis that the proposed action by Siptu was unlawful, as it is contrary to the provisions of the Industrial Relations Act.
It said the union only balloted a portion of its membership and that the planned work stoppage is contrary to existing agreements between the company and the union.
“Siptu’s threatened industrial action is unwarranted and has already caused significant inconvenience for DAA’s airline customers and passengers at Dublin and Cork airports.”
DAA intends to pursue all avenues at its disposal to avert the strike action by Siptu and to keep its airports fully operational, it added.
“DAA remains committed to a fair and sustainable resolution of the pension issue and believes that all parties should engage with the Government-sponsored expert panel without the unnecessary threat of industrial action,” it said.
It also apologised to its customers for the uncertainty and inconvenience that the industrial action has caused.
Earlier this week, Aer Lingus announced a revised flight schedule for next Friday in an effort to minimise the impact of the strike.
The airline said it had hired additional aircraft, retimed flights, rebooked customers on other carriers and cancelled some flights from Dublin, Cork and Shannon airports.
The carrier advised people booked to travel during the period of industrial action to check the status of their flights on the company’s website.