Irish holidaymakers flying to and from the Spanish islands of Majorca, Ibiza and Menorca face major delays this weekend.
A strike by ground staff on Saturday is expected to affect around half of the flights into the Balearic islands, if it goes ahead as planned.
Some 1,000 Spanish workers, including baggage handlers, airport bus drivers and catering staff, plan to stage the first of three 24-hour stoppages from midnight on Friday.
Two other walk-outs have been called for 1 July and 5 July - major travelling days as the height of the holiday season in Spain gets under way.
The industrial action is over a new contract covering wages, working conditions and hours.
