Ryanair threatened that it might slash operations and jobs at some of its German bases if pilots go ahead with Wednesday's planned strike in the country.
The low-cost airline described the latest strike action as "unnecessary" in a statement released on Tuesday. The company also announced that 150 out of 400 flights scheduled to fly to and from Germany on Wednesday had been cancelled.
"These threatened strikes can only damage Ryanair’s business in Germany, and if they continue, will lead to base cuts and job cuts for both German pilots and cabin crew, particularly at some secondary German bases, which are loss making during the winter season," Kenny Jacobs, Ryanair's chief marketing officer, said in the statement.
The company, which counts 11 bases in Germany, did not disclose which might be impacted.
The call for strikes was issued on Monday by German pilots union Vereinigung Cockpit (VC), over a long-standing dispute over pay and working conditions.
Ryanair said that it pays its German pilots 30% more than Eurowings.
"It is unacceptable that a union representing Ryanair’s German pilots, who earn up to €190,000 p.a. and work a 5 day week followed by a 4 day weekend (every week), are now threatening customers travel plans at short notice and without consulting with our German pilots," Jacobs also said.
The budget carrier — Europe's second-largest airline in passenger numbers — was forced to cancel hundreds of flights over the busy summer season due to coordinated strike actions by pilots and cabin crews in several countries including Belgium, Germany, Ireland, Italy, Portugal, Spain and Sweden.
Crew members issued a Charter on July 4 with a list of 34 demands ranging from pay parity across the bases and improved training, to a call for the company to write contracts in the local language.
Since then, Ryanair has reached deals with Irish and Italian pilots, but VC said those deals "cannot be used as a blueprint for a solution in Germany" and accused the airline of trying to buy time with "vague and meaningless statements".
"VC regrets the impact on passengers," the union said in its statement.