Budget airline Ryanair is considering charging passengers to use the toilet on its flights.
Chief executive Michael O'Leary said the no-frills Irish carrier was looking at the possibility of charging one pound to enter its on-board lavatories.
"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 actually have to spend a pound to spend a penny," he told the BBC.
"I don't think there is anybody in history that has got on board a Ryanair aircraft with less than a pound."
Mr O'Leary defended the idea, saying the airline was always keen to find ways of raising "discretionary revenue" to keep airfares down and train stations often charged 20 pence to use their public toilets.
Ryanair has a reputation for its high ancillary charges. Passengers have to pay extra for such things as check-in luggage, most card transactions and refreshments purchased on board its aircraft.