BERLIN, (Reuters) – Security personnel at German airports will hold a one-day strike after four rounds in which negotiations failed to reach an agreement on raising wages. Trade union Verdi stated that this was the result of a fourth round.

Airlines are struggling from high fuel costs and closures of airspace due to war in Ukraine. They had to cancel hundreds more flights from and to Germany because of strikes by security workers last Monday and Tuesday.

Verdi called for a strike at Frankfurt/Berlin, Bremen, Hamburg and Hanover on Tuesday.

Frankfurt was home to around 2.1million passengers in the last month.

Wolfgang Pieper (Verdi negotiator) stated in a statement that Monday, “We did not make any progress in aligning local wages.”

“But, when it came time to raise wages, employers offered far less than what employees wanted.”

The union demands that German employers pay at least 1 Euro an hour to the approximately 25,000 security personnel working in airports in Germany over the next 12 month. Different staff earn the exact same.

BDLS (the association of aviation safety company) stated that Verdi’s requests amounted together to pay hikes of as high as 40%, and they were “utopian.”

Verdi announced that the next round in wage talks is scheduled for Thursday.