PARIS (AP) ― Air France canceled at least half its flights around the world on Monday as pilots began a weeklong strike, highlighting the trouble Europe’s flagship airlines face in keeping up with low-cost competitors.

Air France-KLM, which is the national carrier for France and the Netherlands, said it can ensure just 48 percent of flights Monday, 40 percent on Tuesday and perhaps less later in the week as unions protest against its savings program.

Like Lufthansa, Alitalia, SAS and other national airlines in Europe, Air France-KLM is focusing on cost cuts to remain competitive. That, however, can be difficult in some European countries where laws protecting workers’ rights are strong.

Last week, Air France announced a plan to save 1 billion euros ($1.3 billion) over the next several years, in part by transferring much of its European operations to low-cost subsidiary Transavia.

Air France pilots’ unions are calling foul, and called a weeklong strike starting Monday. They accuse the airline of trying to shift their jobs to countries with lower taxes and cheaper labor ― for example by basing planes for France-Portugal flights in Portugal, instead of France.