Ryanair passengers may face more disruption after pilots based in Germany overwhelmingly backed industrial action in a ballot.
Members of the Vereinigung Cockpit (VC) union voted by 96pc in favour of industrial action. In a statement, they said industrial action "like in other European countries" seems unavoidable.
The ballot result comes as Irish-based pilots are due to hold a fourth 24-hour stoppage this Friday.
The union said any action will be announced at least 24 hours ahead of time to give the travelling public time to make other arrangements.
German-based pilots don't have to give as much notice as Irish-based ones - who are legally required to give their employer seven days' notice.
The union said they are demanding working conditions similar to those found at competitors, including TUIfly.
"To avoid industrial action, we are offering Ryanair a final deadline to submit a workable proposal by August 6," said the union in a statement.
"Unfortunately, so far Ryanair has not made any proposal with which we could work."
Chairman of industrial relations at Vereinigung Cockpit, Ingolf Schumacher, said no progress was made during last Friday's talks.
"We implore upon Ryanair to reverse its present way of behaving like a wrong-way driver towards pilot and cabin crew unions throughout Europe," he said.
A Ryanair spokesperson said it wrote to VC and invited it to another meeting next week. "We hope we can make further progress in concluding a collective labour agreement with our pilots in Germany," she said.
Meanwhile, Ryanair has invited the union for the striking Irish-based pilots - Forsa - to talks after this week's strike.
The airline said even if the strike is called off at this stage, the damage to its business has already been done.
It has cancelled 20 of 300 flights due to take off on Friday.
The airline said the repeated strikes have damaged its business and led to 300 pilots and cabin crew receiving protective notice last week.
Up to 3,500 passengers booked on the cancelled flights have been reaccommodated on other flights or refunded.