(Bloomberg) -- Ryanair Holdings Plc Chief Executive Officer Michael O’Leary said the Irish carrier could almost double its passenger capacity through the rest of the summer as the European Union reopens for travel.

Europe’s biggest discount airline expects to attract up to 9 million passengers in July and August compared with 5 million in June and just 1.7 million in May, O’Leary told Bloomberg Television in an interview Thursday.

“We’re seeing a very strong recovery in bookings, German leisure, Benelux leisure, Scandinavian leisure, heading to the beaches of Portugal, Spain, Greece and Italy,” O’Leary said. “We expect that to continue into July and August, which should make for a reasonable recovery.”

Demand has been spurred as the EU rolls out its Digital Covid Certificate from July 1, allowing travelers to move between member states provided they are fully vaccinated, have recovered from the virus or can show a negative test result. The reopening marks a step toward securing vital summer revenue after a series of false starts amid the spread of new viral variants.

Still, only about 50% of available seats have been booked for July and 30% for August, compared with up to 70% normally, putting the focus on luring back passengers to maximize sales and leading fares to be cut, O’Leary said.

Lagging Behind

The CEO said that the U.K. and Ireland are lagging behind the recovery in mainland Europe. Britain has been overly cautious in limiting movement in response to the Delta variant of the virus, he said, while predicting that more countries will be added to its quarantine-free “green list” from July 19.

Allowing unfettered travel for vaccinated passengers, something currently under discussion in the U.K., would spur “a very strong recovery” in demand and Ryanair would restore capacity to the country that’s been deployed elsewhere, he said, while cautioning that the EU could impose limits of its own.

Malta, on the U.K. green list, last week imposed a quarantine for non-vaccinated Britons, with Portugal following suit, though it had already been moved to the amber category requiring people to self-isolate on their return to the U.K. Spain’s green-listed Balearic Islands will let British tourists in if they test negative for Covid-19 on arrival.

O’Leary said the situation could be eased if the U.K. health service’s own coronavirus pass was to be made interoperable with the EU vaccine certificate.

That’s something several EU states pushed the European Commission to address at a meeting of ambassadors on Wednesday, according to a diplomatic memo seen by Bloomberg.

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