The Verdi trade union has called for a strike at Frankfurt, Munich, Cologne and Bremen airports today, forcing Lufthansa to cancel nearly 1,000 flights.
Ground handling services, support services and part of the airport fire brigade will be on strike until 18:00.
As a result, Lufthansa has cancelled 800 out of the 1,600 scheduled flights, including 58 long-haul flights.
The cancellations will affect about 90,000 passengers.
Flight operations are scheduled to resume normal services on Wednesday.
Lufthansa passengers are requested to check the status of their flights before leaving for the airport.
Passengers who have provided Lufthansa with their contact details will be actively notified of changes by SMS or e-mail, the airline said.
Passengers whose flights are not affected by the strike are also asked to allow more time and to come to the airport earlier, as waiting times are to be expected.
A statement from the carrier said Lufthansa could not comprehend Verdi’s threat to carry out such a massive strike.
“It is completely unacceptable for the union to impose this conflict on uninvolved passengers.
“Lufthansa is not a part of this collective bargaining conflict, but unfortunately our customers and our company are being affected by the consequences of this dispute,” said Bettina Volkens, board member, Lufthansa.
“The nature and extent of the widespread and full-day strike is inappropriate and unreasonable at this time.”