Ryanair boss Michael O’Leary hit out at online agents this week, calling them “a bunch of scam artists” and threatening: “We’ll bury the bastards.”

The airline launched legal action against On The Beach last month, accusing it of screen-scraping, and O’Leary said there would be no let-up.

The action against On The Beach was merely the latest in a series that has seen Ryanair log proceedings against 36 companies at Dublin’s high court.

O’Leary said: “We will continue until we bury the bastards. They are screen-scrapers masquerading as price-comparison sites.

"They are a bunch of scam artists. They are the greatest source of passenger complaints. They flip prices up 10%-15%, they don’t pass on terms and conditions, and we don’t get passengers’ email addresses.

“We’ve made six complaints to the Office of Fair Trading, but it has done nothing. We’ll nail those bastards to every stake. But it will take a bit of time.”

On The Beach has rejected Ryanair’s claims, saying: “We’ll robustly refute the allegations. We categorically deny there is any basis to them.”

O’Leary also hit out at complaints about Ryanair’s €60 charge to print a boarding pass for passengers who fail 
to print their own.

Passenger Suzy McLeod kicked up a social-media storm and made the national press when Ryanair charged her £236 to print boarding passes for her family to fly home from Alicante last month.

But O’Leary said: “If you don’t comply with our terms and conditions, you’re not flying. Thanks, Mrs McLeod, but it was your f*** up. She paid £200 for being an idiot.”

O’Leary added: “We tell passengers: print your boarding card or bugger off.”

The Ryanair boss, speaking in London, demanded the Civil Aviation Authority  reduce landing charges at Stansted ahead of the airport’s sale by owner BAA. He said: “Most of the consortia [interested in buying Stansted] want us to take a stake. [But] we’ll take nothing more than 24.99%.”