Elbers warned that COVID-19 will limit flights more extensively than the 20-25% drop it had anticipated for next year.

"We now expect even lower production, which ultimately means we need fewer people", Elbers said in his message, seen by Reuters.

"Another 10% drop in production (so 30-35% down from 2019) would mean around another 1,500 jobs less."

KLM on Thursday submitted a restructuring plan to the Dutch state, a condition of the 3.4 billion euros (3.10 billion pounds) package in aid it is receiving to avoid bankruptcy amid the COVID-19 pandemic.

KLM said it would cut costs by 15%, as well as reduce carbon dioxide emissions by 50% by 2030. KLM is cutting its workforce by 20%, including 4,500 jobs this year.

(Reporting by Bart Meijer, editing by Louise Heavens)