Lufthansa almost stopped air traffic on Wednesday in Munich and Frankfurt because of the warning strike by its ground staff.

"Lufthansa has had to cancel almost the entire flight program at the hubs in Frankfurt and Munich for Wednesday," the airline announced on Tuesday.

The warning strike announced by the Verdi union in the collective bargaining conflict has massive effects during the peak travel season.

Lufthansa is canceling a total of 678 flights at Frankfurt Airport, 32 of them on Tuesday.

At the hub in Munich there were a total of 345 flights on both days.

"The early escalation after just two days of negotiations in what has so far been a constructive round of collective bargaining is causing enormous damage," said Lufthansa Chief Human Resources Officer Michael Niggemann.

Individual flight cancellations and delays are still possible on Thursday and Friday.

Strike from 3:45 a.m

In addition to the hubs in Frankfurt and Munich, Düsseldorf, Hamburg, Berlin, Bremen, Hanover, Stuttgart and Cologne are also affected.

The Lufthansa Group usually maintains smaller units there, which also offer their services to other airlines.

In Bavaria, Friday is the last day of school before the summer holidays.

Passengers without transfers should not come to the airports because "little if any" service counters will be open there, the company warned.

Passengers complained online about short-term cancellations of intercontinental flights to the United States or Hong Kong.

These are usually the last flights that Lufthansa cancels in the event of a strike.

Lufthansa warned transfer passengers against flying to the German hubs without a connecting flight.

There is a risk that guests will not be able to travel there for several hours or days.

The all-day strike is scheduled to begin at 3:45 a.m. on Wednesday morning, as Verdi announced.

Very different groups of employees are called upon, such as counter staff, aircraft technicians or the drivers of the huge tow tractors that push aircraft into the correct positions at the airport.

Without these services, the jets cannot take off any more than they do without pilots or cabin crew.

Staff shortages and strong demand

The first strike at Lufthansa after the Corona shock comes against the background of a partially chaotic restart in the industry.

Personnel bottlenecks and a strong demand for vacations have already led to considerable handling problems this summer without any strikes.

Verdi mainly blames mismanagement at airports and airlines for this.

The Lufthansa airline boss Jens Ritter, on the other hand, sees the progress made by the strike announcement in question.

The walkout will burden customers and staff beyond the day of the strike, said Ritter on the LinkedIn platform.

According to its own information, Lufthansa has offered a two-stage flat-rate salary increase of a total of 250 euros for a period of 18 months, which will be accompanied by a profit-related increase of 2 percent from July next year.

With a monthly base salary of 3,000 euros, this would result in an increase of 9 to 11 percent, the company calculated.

Verdi negotiator Christine Behle described the example as "prettily calculated".

For other salary ranges, the increase is only around four percent and thus brings real wage losses for the employees, she said "Stuttgarter Zeitung" and "Stuttgarter Nachrichten" (Tuesday).

The union demands 9.5 percent more money in the wage tables for a period of 12 months, but at least 350 euros.