Ryanair has been grappling with staff unrest since it recognised trade unions for the first time in December 2017 Germany's Ryanair pilots will join an unprecedented wave of strikes against the no-frills carrier across Europe on Friday, escalating a row over pay and conditions at the height of the summer season.
Germany's powerful Cockpit union said it had asked its 400 Ryanair pilots to walk off the job for 24 hours from 03:01 am (0101 GMT) on Friday, affecting all of the airline's outbound flights.
"We are extremely sorry for the affected passengers. The responsibility lies with Ryanair management," Cockpit president Martin Locher told a press conference on Wednesday.
The move piles pressure on the Irish budget airline after pilots in Ireland, Sweden and Belgium also vowed to strike on August 10, promising major disruptions for thousands of holidaymakers.
Europe's second biggest airline has been grappling with staff unrest since it recognised trade unions for the first time in December 2017, in a bid to ward off widespread strikes over the Christmas period.
But unions say their demands for better wages and fairer contracts have gone unheard, and no progress has been made despite months of negotiations.
Germany's Cockpit union said Ryanair management had failed to respond to a Tuesday deadline for an improved offer, leaving them with no choice but to strike.
"There can be no improvements without increasing staff costs," Locher said, but added that this has been "categorically" rejected by Ryanair.
"At the same time, Ryanair has at no stage signalled where there might be leeway to find solutions. Ryanair alone is responsible for the escalation we are now seeing."
Ryanair is due to hold its own press conference in Frankfurt at 1:30 pm (1130 GMT).
Ahead of Friday's disruptions, the carrier has already cancelled 146 flights out 2,400 scheduled in Europe.
Unions complain that Ryanair hires most of its foreign staff under Irish contracts, leaving them ineligible for social benefits at home Solidarity
Ryanair pilots have long claimed that they earn less than their counterparts at rival budget airlines.
Unions also want the 33-year-old airline to give contractors the same work conditions as staff employees.
Another key complaint of workers based in countries other than Ireland is the fact that Ryanair employs them under Irish legislation, arguing most of its employees work on board Irish planes and are therefore covered by Irish law.
Staff counter however that this creates huge insecurity for them, blocking their access to state benefits in their country.
Ryanair, which flies in 37 countries and carried 130 million passengers last year, has previously said it remained open to further talks with pilot representatives to discuss union recognition and collective labour agreements.
But its combative chief executive Michael O'Leary has also warned the airline may shift jobs and planes to more profitable areas if the strikes continue.
The carrier was already hit by a round of strikes last month disrupting 600 flights in Belgium, Ireland, Italy, Portugal and Spain.
It said the 100,000 affected passengers had all been put on alternative flights or would receive refunds.
After those stoppages Ryanair threatened to move part of its Dublin fleet to Poland if the turmoil continues, which could cost 300 jobs, including 100 pilot positions.
Germany's Cockpit union slammed what it saw as Ryanair's attempts to play countries against each other.
"It has to stop that Ryanair can just shift pilots to other European locations from one day to the next," said Cockpit's head of industrial relations Ingolf Schumacher, welcoming the solidarity among European unions.
"We are pleased that our colleagues are striking side by side with us."
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