Cabin crew at Lufthansa, Europe’s largest airline, say they won’t give out locations or times for a planned strike sometime Friday.

The union representing workers for the German airline says it will only give six hours notice before striking, preventing Lufthansa officials from having a chance to prepare for the strike.

The idea is that Lufthansa will not have sufficient time to prepare and dispatch replacement crews, increasing the effectiveness of the strike action.

The dispute is primarily over money, with the union also looking for a guarantee that the company won’t outsource jobs.

Lufthansa operates more than 1,800 flights around the world.