Ryanair expects a "pretty aggressive" air fare battle in the coming months, with some routes possibly falling below €9.99.
"I think it'll get very aggressive on specific routes…I think there's going to be a bit of a battleground for the business traveller with fantastic fares for those business travellers," chief marketing officer Kenny Jacobs said.
"It's at €9.99 already, even on some routes across Europe we're looking at more aggressive pricing…you can expect that to scale up once our winter schedule kicks in at the end of October."
Mr Jacobs said he expects an aggressive price war on the route from Dublin to Brussels-Zavantem, and said flights from Dublin to Madrid, Barcelona and London "will always be competitive."
Flights from Dublin currently priced at €9.99 go to Manchester, Glasgow Prestwick, Birmingham, Glasgow International and Leeds Bradford.
There is an additional fee of 20c if customers pay via credit card or PayPal.
Mr Jacobs' comments came after the airline's AGM yesterday, at which chief executive Michael O'Leary said he has signed a new five-year contract to remain in charge of the airline.
The Ryanair boss had previously been on a 12-month rolling contract.
"They've asked me to give a five-year commitment while we bed down the new management team - I said fine."
Mr O'Leary told shareholders that his pay rose 20pc to €1.8m in the last year, despite profits falling 8pc.
He said that while he is "clearly very well remunerated," he earns less than half the package of the chief of British Airways parent IAG - fellow Irishman Willie Walsh - who's responsible for fewer passengers.
Mr O'Leary said Ryanair has fundamentally changed the way it does business in the last 12 months.
"If I'd known that being nicer to our customers was going to result in higher load factors...I'd have been much nicer to our customers some considerable time ago," he said.
The airline said profits for its current financial year will be at the upper end of the €620m to €650m guidance given in August.