Berlin’s airport said it has canceled all passenger flights Wednesday because of a strike organized by the Verdi union, severing the German capital from international air travel. 

The dispute means that 300 takeoffs and landings won’t be possible, affecting about 35,000 passengers, according to a statement by the BER airport operator. Among the airport’s biggest airlines are discount specialist EasyJet Plc and Deutsche Lufthansa AG. 

A spokesperson for Lufthansa said the airline was offering passengers rebooked flights on Thursday or train alternatives.

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.

“The workers are massively overloaded,” Enrico Ruemker, leader of the Verdi union’s transport section in Berlin, said by phone, adding that there are no further walkouts planned to coincide with the looming winter holiday in the capital next week. “This is the airlines’ fault for pursuing strategies of offering the cheapest tickets possible.”

The latest disruption at Berlin follows a tumultuous summer of strikes and delays at Germany’s biggest airports after labor unions pushed for better pay deals to offset the cost of living squeeze. German inflation rates have soared after Russia’s invasion of Ukraine drove gas and other energy prices higher.

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. Frankfurt, by comparison, handled almost 49 million passengers last year.

Air traffic has come back from the pandemic, with leisure travel picking up most notably. The surge caused chaos at airports across Europe last year after operators and ground personnel struggled to meet demand.