Dublin ? When nature calls at 30,000 feet, is $1.40 a wee price to pay? Or could it force passengers without correct change into a whole new kind of holding pattern?

The head of budget European airline Ryanair unleashed a flood of indignation and potty humor Friday when he suggested that future passengers might be obliged to insert a British pound coin for access to the lavatory to get some in-flight relief.

Airline chief Michael O’Leary suggested that installing pay toilets would lower ticket costs and make flying, somehow, easier for all.

Not even his own aides seemed to be sure if he was serious or pursuing his penchant for making brazen declarations to get free publicity for Ryanair.

“One thing we have looked at in the past, and are looking at again, is the possibility of maybe putting a coin slot on the toilet door, so that people might have to actually spend a pound to ‘spend a penny’ in future,” O’Leary said, using a British euphemism for going to the bathroom.

When asked during an interview on BBC Television what would happen if a customer really had to go but didn’t have correct change, O’Leary dismissed the scenario as implausible.

“I don’t think there’s anybody in history (who has) gone on board a Ryanair aircraft with less than a pound,” he said.

O’Leary spokesman Stephen McNamara said his boss often spoke tongue in cheek — but he then defended the idea of in-flight pay toilets as part of a logical trend.

“Michael makes a lot of this stuff up as he goes along and, while this has been discussed internally, there are no immediate plans to introduce it,” McNamara said, adding, “Passengers using train and bus stations are already accustomed to paying to use the toilet, so why not on airplanes? Not everyone uses the toilet on board one of our flights, but those that do could help to reduce airfares for all passengers.”

Analysts agreed that the man who pioneered charging passengers to check bags, to use a check-in desk and even to use a credit or debit card to make an online booking just might be serious about mile-high toilet extortion.

Howard Wheeldon, senior strategist at BGC Partners in London, said there might be some truth to O’Leary’s statement.

“This begs a simple question retort of: Is there absolutely nothing that this airline won’t do? Not really, so if you are thinking about flying cattle-class Ryanair in future, beware,” he said.