The UK Civil Aviation Authority (CAA) has ordered Ryanair to comply with its instructions on air passengers’ rights by 17:00 on Friday October 29 or face legal action.

The CAA demanded Ryanair issue a press release and update its website to clarify the options available to customers affected by the carrier’s two sets of flight cancellations in the past fortnight.

CAA chief executive Andrew Haines first warned Ryanair by letter on Wednesday of the regulator’s intention to take legal action over its non-compliance with European air passengers’ rights under regulation EU261.

That followed Ryanair’s announcement of a new round of flight cancellations affecting 400,000 passengers as it withdrew 25 aircraft from service from November to March next year.

The latest cancellations followed the earlier cancellation of flights due to carry 315,000 passengers.

In a long statement declaring an “end to rostering cancellations” due to the cut back in its fleet, Ryanair chief executive Michael O’Leary declared: “All of the passengers who have been affected have been offered re-accommodation or full refunds and their applicable EU261 entitlements.”

However, the CAA write to Ryanair on Wednesday stating: “The CAA has launched enforcement action against Ryanair for persistently misleading passengers with inaccurate information regarding their rights.

“In announcing thousands more cancellations, the airline has again failed to provide customers with the necessary and accurate information.

“Separately, we are continuing to investigate the airline’s re-routing policy.”

Haines said: “There are clear laws in place. We have made this clear to Ryanair, who are well aware of their legal obligations. The information Ryanair published today again fails to make this clear.”

Ryanair responded with a brief statement saying: “We will be meeting with the CAA and will fully comply with whatever requirements they ask us to.”

However, the CAA wrote to Ryanair again on Thursday, noting the airline’s claim that “We already comply fully with EU261 legislation” and stating: “We have been seeking information from Ryanair since September 21.”

The latest letter imposed the deadline for compliance and listed a series of requirements, including that Ryanair: “Issue a press release explaining how it will re-route passengers and the criteria it will apply to re-route passengers on other airlines . . . [and] a statement that Ryanair will reimburse any out-of-pocket expenses incurred by passengers as a result of the cancellations.”

The CAA also noted: “We have seen examples of emails set to passengers affected by cancelled flights [which] omitted material information for passengers about their rights.”

It ordered Ryanair to re-contact all affected passengers by October 4 with the full and correct information.

Ryanair’s latest statement did mark a retreat from O’Leary’s earlier threats to force pilots to give back a week’s leave, made at the carrier’s annual general meeting last week.

The airline said: “We will not need pilots to give up one week of their well-earned annual leave from November. We have assured them that all their annual leave is protected.”

Ryanair also pledged: “In order to focus on repairing this rostering problem, Ryanair will eliminate all management distractions starting with its interest in Alitalia.

“We have notified the Alitalia bankruptcy commissions that we will not be pursuing our interest in Alitalia.”