German carrier Lufthansa says it is canceling almost all passenger and cargo flights Friday from its two biggest hubs, Frankfurt and Munich, due to planned strike action by pilots, writes CBS NEWS.

A union representing Lufthansa pilots said that they will stage a walk-out after demands for a pay increase were rejected by management.

Lufthansa said some 800 flights would be canceled, affecting many travelers returning at the end of the summer vacation. The airline’s budget carrier Eurowings would not be affected, it said.

The union Vereinigung Cockpit accused Lufthansa on Thursday of failing to improve on the company’s previous offer, leaving pilots no choice but to go on strike to press their demands.

According to Lufthansa, the company had offered a one-off increase of 900 euros ($900), amounting to a 5% increase for senior pilots and an 18% increase for those starting the profession.