Ryanair has responded to threats of legal action from the aviation regulator by emailing customers affected by flight cancellations to clarify their rights.
The airline told passengers they can receive a refund or be transferred on to other flights or travel by trains, buses or car hire.
The Civil Aviation Authority (CAA), which on Thursday accused the Dublin-based carrier of “not complying with the law” over its handling of the fiasco, claimed the airline had “capitulated” after enforcement action was launched.
It had accused Ryanair of not telling passengers that under EU261 rules they were entitled to be re-routed by another carrier.
Ryanair’s offer to passengers features several conditions, including assessing the cost of flights on other airlines “on a case by case basis” before bookings are made.
Alex Neill, a managing director at consumer group Which?, said passengers face a “potential minefield” to reach their destination.
He added: “It still smacks of a lingering reluctance to do the right thing.”
An extra 18,000 flights for the winter season were cancelled by Ryanair on Wednesday – a move that will hit 400,000 customers.
Ryanair said the cancellations were brought about because of an error with pilot holiday rosters and insisted the latest reduction in its schedule will “eliminate all risk of further flight cancellations”.