Ground staff and cabin crew at Spain's Iberia are beginning 15 days of strikes in protest at plans to lay off 3,800 workers.
The airline says the stoppages, to be staged over three weeks, will lead to more than 1,200 flight cancellations.
A government decree on minimum services guarantees 90% of long-haul flights, 61% of medium-haul and 46% of domestic flights.
Iberia claims economic difficulties oblige it to make lay-offs.
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