The operator of Berlin’s largest airport expects strike action to bring all regular flight traffic to a standstill on Wednesday as ground crews, services staff and security personnel walk off the job.

Passengers scheduled to fly to or from Berlin-Brandenburg airport on Jan. 25 should inform themselves about the status of their flights, the operator said in a statement on Monday. Some 300 takeoffs and landings, carrying about 35,000 passengers, were originally planned for Wednesday, it said.

Labor union Verdi called the warning strike, citing dissatisfaction with proposals made in three rounds of collective bargaining negotiations by the airport’s management. It’s demanding an increase of €500 ($543) a month for ground services employees over a 12-month period as well as higher bonuses for air security personnel who work weekends and public holidays.

Berlin-Brandenburg opened in 2020 after eight years of construction delays. More than 19 million passengers passed through the airport in 2022, according to the operator’s website.