Stansted-based Ryanair is facing enforcement action by the Civil Aviation authority for failing to give customers accurate information on their rights.
It said the company falsely claimed it did not have to re-route passengers on other airlines, particularly when there are no other services available.
It follows yesterday's announcement that the airline was cancelling 18,000 additional flights and suspending some routes, like Stansted to Glasgow and Edinburgh until next year.
The firm says it will meet with the regulator.
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Ryanair has agreed to implement measures to ensure all passengers affected by flight cancellations are "fully aware" of their rights.
The Civil Aviation Authority has accused Stansted-based Ryanair of failing to respond to their request of an urgent meeting.
The aviation regulator has given Ryanair until 5pm today to sort out compensation for hundreds of thousands hit by cancellations.