Ryanair is planning to run flights where passengers stand during the journey at a cost of just £5 per ticket.
Michael O'Leary, the airline's chief executive, will set out proposals today that include charging customers to use the loo.
A standing area with "vertical seats" will be introduced at the back of its fleet of 250 planes.
He said that charging customers £1 to make use of facilities would encourage travellers on one hour flights to use lavatories at the airport instead of on the aircraft.
The Irishman said he intended to introduce coin-operated loos and added: "The other change we've been looking at is taking out the last 10 rows of seats so we will have 15 rows of seats and the equivalent of 10 rows of standing area."
A Ryanair spokesman said that Boeing had been consulted over refitting the fleet with "vertical seats" which would allow passengers to be strapped in while standing up, which would cost between £4 and £8 per person.
Safety testing will be carried out next year.
However, a spokesman for the Civil Aviation Authority said the plans would struggle to meet safety requirements.
He said: "It's aviation law that people have to have a seat-belt on from take-off and landing so they would have to be in a seat. I don't know how Mr O'Leary would get around that one. During turbulence passengers also have to have a seat-belt on."
Mr O'Leary was interviewed for ITV's How to Beat the Budget Airlines which airs on Thursday night at 7.30pm.