Ryanair’s Michael O’ Leary has asked four other competing European airlines  to display each other’s fares on their websites in a bid to squeeze out fare comparison websites such as Expedia, Sky Scanner and Google Flights.

In a letter understood to have been sent to IAG, Air France/KLM, Lufthansa and Easyjet, Mr O’Leary says, “if the airlines were competitive and had a competent digital offering, those kind of websites shouldn’t exist.”

He continues: "I think it is something the big airlines could and should work together on, because I think it makes no sense for third-party price comparison websites [to be] out there."

The airline has predicted that its prices will fall by between 4 and 8 percent in the second half of this year, as savings from cheap fuel costs are passed on to customers.

The airline has paid an average of $91 per-barrel forward buying for 2016 - but it has bought fuel for 2017 at $66 per barrel - saving €250m.

The Ryanair-boss has also recently combined with other major European airlines to lobby the EU on regulatory and industrial relations issues such as air traffic controller strikes.