Ryanair has attacked Cornwall County Council over its controversial departure tax at Newquay Airport.
Ryanair says the £5 charge is deterring visitors to Cornwall
The council started charging passengers a £5 airport fee in 2005 to improve facilities at the airport.
Ryanair, which halved flights from the airport in response, said Newquay had lost 80,000 passengers.
The council said it would not be dropping the fee which it said had had no overall adverse effect on the number of people using the airport.
Ryanair marketing manager Caroline Baldwin, said: "A one-way Ryanair flight from Newquay to Stansted can cost under £10 before tax.
"The levy effectively adds 50% to the pre-tax travel cost."
She said that with increased funding from the South West Regional Development Agency, there was no longer a need for the levy.
But the council said the fee brought in an extra £160,000 a month which had been used to borrow £10m.
Some of that has been used to fund an expanded passenger terminal.
Other operators at Newquay, Air South West, Flybe and Skybus, have accepted the charge.