Trade union Verdi announced the strike for 52,000 ground and cabin personnel on Friday morning. More than 90 percent of the union members voted to continue putting pressure on the airline in the ongoing wage dispute, Verdi leader Erhard Ott said on Friday in Berlin.
The strikes begin on midnight Sunday and will last indefinitely, including cabin, check-in, maintenance, catering and cargo workers, Ott added.
Airports in Berlin, Bremen, Düsseldorf, Frankfurt, Hamburg, Hannover, Leipzig, Munich, Nuremberg and Stuttgart will all be effected by the strike.
Lufthansa is reportedly bracing for the strike with a detailed emergency service plan.
The Friday edition of Rheinische Post reported that Lufthansa's management had drawn up measures to ensure at least 75 percent of flights could continue if ground and cabin personnel walk off the job next week.
The emergency plan calls for employees from other companies to take over check-in duties.
The paper said Lufthansa would attempt to counter a strike by maintenance staff – reportedly the worst scenario for the airline – by pushing all traffic through the hubs Frankfurt, Munich and Zurich. Lufthansa would shift a lot of domestic German flights to trains and Austria Airlines would also carry some passengers.
A Lufthansa spokeswoman would not confirm the emergency plans, but said the airline would naturally be prepared for any strike.