Dublin Airport passenger fees look set to fall from almost €9 to €7.50.
The Commission for Aviation Regulation is recommending the reduction.
It believes the proposed drop is in "the best interests of passengers to ensure value for money".
It's proposing a maximum price of €7.50 per passenger from next year, until 2024.
Current Dublin Airport Passenger Fees
That's a 15% cut on the current fee of €8.81.
The DAA is "extremely concerned" by what it calls a "fundamentally flawed" proposal.
It points out that the regulator wants it to grow business, but with less money.
The DAA said the rate cut "does not take account of the current reality at Dublin Airport".
It also warned it could "jeopardise the investments in new facilities that are required to cope with growing demand".
DAA Chief Executive, Dalton Philips, said the proposal is:
"Absolutely not in the best interests of passengers, airlines or the wider Irish economy".
"Brexit creates unprecedented uncertainties for the Irish economy and in that context, we should be investing at Dublin Airport and improving and deepening Ireland's links with the world", he said.
