The union of German air traffic controllers on Monday made a second attempt to call a strike during the busy summer holiday season.
The GdF union of employees at the German air traffic control authority called on its members to strike for six hours from 0400 GMT until 1000 GMT on Tuesday to push for higher wages.
Air traffic control authority DFS said it would apply for a temporary injunction to prevent the strike.
"There are still some demands that we think are illegal," a spokeswoman for DFS said.
Last week, the air traffic controllers' union called for a six-hour strike that could have disrupted thousands of flights, but it was called off after a court injunction.
On a typical day in August, around 600,000 people use Germany's airports, according to travel association DRV. All but three of Germany's 16 federal states are on school holidays.
Lufthansa said it regretted the uncertainty caused for passengers by the strike.
"We have already started to make first preparations and, should it come to a strike, we will do everything in our power to minimise disruption," a spokesman said.
Should a strike take place, airlines and travel companies would likely bring forward flights or delay them until the afternoon. Others could be rerouted to avoid German airspace.
GdF wants a 6.5 percent pay rise over 12 months, and has asked that pay be linked to the number of years in service.
It rejected the latest offer from the DFS for a raise of 3.2 percent plus a one-time payment this year, and an increase of at least 2 percent next year.
The DFS had offered fresh talks for this week, and said on Monday it was still prepared to sit down with the union. The union said it would not return to the negotiating table unless there was a change in circumstances.
Faced with a lack of sympathy for the planned strikes, the union also said the strike was not just about more pay for air traffic controllers, but all employees of the DFS.
Airlines have previously successfully fended off strikes using the courts.
Last year, pilots of German flagship carrier Lufthansa and the country's No.2 carrier Air Berlin were forced by judges to call off or curtail strikes.
Analysts have estimated a six-hour strike could cost Lufthansa a double-digit million euro amount, but the impact would be small compared with disruption caused by last year's volcanic ash cloud or uprisings in North Africa this year.
An 18-month dispute at International Airlines Group's British Airways over pay and conditions for cabin crew resulted in 22 days of strikes and cost BA more than 150 million pounds ($244 million).
ReutersLast Mod: 08 Ağustos 2011, 12:26