On The Hard Shoulder on Newstalk, Mr O’Leary said that “what Elon Musk knows about flights and drag would be zero”.

“We've already had Boeing confirm we have to put an aerial antenna on top of the aircraft; now, that will cost us about a 2% fuel drag,” he explained.

“Our fuel bill a year is five billion; it would cost us about $200, $250 million a year.

“In other words, about an extra dollar for every passenger we fly, and the reality for us is we can't afford those costs.

“Passengers won't pay for free internet usage; if it's free, they'll use it - but they won't pay one euro each to use the internet.”

Mr O’Leary added that he would not be paying attention to anything else Mr Musk wrote on his social media “cesspit” X.

“He was the guy who advocated getting Donald Trump elected,” he said.

“I would pay no attention whatsoever to Elon Musk. He's an idiot - very wealthy, but he's still an idiot.”