RYANAIR has been ordered to guarantee 100% of flights between mainland Spain and the islands during its two-day cabin crew strike and 59% of international connections.
Between 35% and 59% of internal flights are required to run during then industrial action on July 25 and 26.
All flights due to take off before the strike starts, even if they are scheduled to land during strike hours, must be guaranteed.
The airline is expected to take whatever legal steps it can to ensure minimal disruption, including placing passengers on flights operated by other airlines.
Passengers who booked before strike action was announced and would have to pay more to travel with another airline must be given the difference by Ryanair.
A total of 1,807 cabin crew in Spain have been summoned to strike, based in Málaga, Valencia, Ibiza, Sevilla, Alicante, Girona, Mallorca, Gran Canaria, Lanzarote, Madrid, Santiago de Compostela, and Barcelona.