By Friederike Heine

BERLIN (Reuters) -Nearly all of Germany’s airports will be hit by a 24-hour strike on Monday, likely impacting hundreds of thousands of passengers, after trade union Verdi called for employees in the public sector and ground handling to walk out.

The planned strike marks a major escalation in negotiations after Verdi staged several walk-outs at some airports in Germany, including a two-day strike at Munich, last month.

The union warned in a statement on Friday that passengers should prepare for massive restrictions on departures and arrivals, including flight cancellations.

The association of Germany’s airport operators ADV said the travel plans of hundreds of thousands of people would be disrupted. The short notice also means that “passengers will hardly have a chance to find alternative routes”.

The country’s two busiest airports – Frankfurt and Munich – were scheduled to operate 2,000 flights on Monday, a spokesperson for the ADV airport association told Reuters.

Frankfurt Airport said there would very likely be no departures from Germany’s main hub. It advised passengers to refrain from coming to the airport and called on those transferring through the airport to check the flight status on their airline’s website.

More than 150,000 passengers would be affected, it added.

Other airports affected on Monday include Stuttgart, Cologne/Bonn and Duesseldorf, Dortmund, Hanover, Bremen, Hamburg, Berlin and Leipzig-Halle.

Germany’s air traffic control operator, DFS, said it would not be directly affected by the strikes.

The union, which is demanding an 8% wage increase, or at least an increase of 350 euros ($380) more per month, as well as higher bonuses and additional time off, said it called the warning strike after a second round of collective bargaining failed last month.

Employers have rejected the demands as unaffordable.

Negotiations are due to continue later this month. ($1 = 0.9216 euros)

(Writing by Miranda Murray, Editing by Friederike Heine, Ludwig Burger, Alex Richardson, William Maclean)