Taxi Drivers say changes at Dublin Airport will reduce availability and increase wait times for passengers.
A new pre-booked taxi permit system comes into effect next week.
It means drivers will need to use it if they want to take fares.
Currently, they can take immediate booking requests on the ground of the airport, but this will stop them.
Charlie Gleeson from the taxi app FreeNow says drivers are already paying to pick up passengers:
"83% of drivers are saying they're less likely to pick up passengers from Dublin Airport on the back of this announcement. So it's going to be really important that we work closely with the DAA to ensure that taxi supply isn't compromised and passenger wait times don't increase."