Wizz said the program has proven popular with people who have the ability to book last minute and are looking for cheap travel options, as well as being a useful tool for filling seats that would otherwise have been left vacant .

The airline insists this is the most effective way to ensure planes are as full as possible – reducing each passenger’s carbon footprint.

Mr Váradi defended the decision to expand the programme. “It’s just propaganda. People want to travel. The real question is how to achieve this with the lowest impact on the environment,” he said.

“You go to these COP meetings to discuss carbon emissions and when you look around the airport you see hundreds of private jets. While we have just been recognized as having the lowest carbon footprint of any airline in Europe. »

Expansion of the service will be officially announced once the systems to support a larger program are in place.

Mr Váradi said the program had proven “popular across the board”, with members ranging from leisure travelers and business people to migrant workers.

He enjoyed particular success with the so-called digital nomadswho leverage the latest communications technologies to work remotely and travel freely.

“These guys can be anywhere because they don’t stick to one physical location. They don’t travel for a particular purpose, it’s a lifestyle decision.

The boss said he was initially concerned that the benefits of the program might have been offset by the loss of some full-price bookings, but that was not the case.

“You will cannibalize existing traffic because people would have paid more for their tickets, but they will also occupy empty seats that you would have flown empty,” he added.

“We needed to understand how customers would behave and how that would affect booking profiles, but it’s profitable and we think it’s a good deal for consumers and for us.”