According to the head of the Irish airline, cases of violence on board have increased this summer, with incidents occurring every week due to a combination of alcohol with "powder and tablets".

"It's not that easy for airlines to spot people who are drunk at the boarding gate, especially if they're boarding with two or three other people. As long as they can stand up and mingle, they can get through. Then, when the plane takes off, we see the bad behaviour," said O'Leary, in The Telegraph.

"We don't allow people to drive drunk, and yet we continue to put them on planes at 33,000 feet," he said.

For the CEO of the low-cost airline, the number of assaults between passengers could decrease if the sale of more than two alcoholic drinks per boarding pass was prohibited.

"Airports are opposed to this measure and say that their bars don't serve drunk passengers. But they serve the relatives of drunk passengers," he said, adding that flights from the United Kingdom are particularly prone to violence, especially in so-called "party destinations".

O'Leary assured that the measure "will not affect the profits" of airports, because "bars can continue to sell their drinks and food".