(FILES) In this file photo taken on November 12, 2020 an employee of German airline Lufthansa wears a face protection mask at a boarding counter of the Franz-Josef-Strauss Airport in Munich, southern Germany. - German national carrier Lufthansa is braced for further travel upheaval as the country's powerful Verdi union called on ground crew to strike on July 27, 2022 in a row over higher wages. The stoppage from 0145 GMT on July 27 until 0400 GMT on July 28 will cause "major flight cancellations and delays", Verdi warned on Monday, July 25. The walkout at one of Europe's largest airlines adds to a troubled summer season at airports across the continent as eased coronavirus restrictions have boosted tourism demand, but chronic staff shortages have left passengers grappling with flight disruptions, long queues and lost luggage. (Photo by Christof STACHE / AFP)