Charging £1 for dropping off and picking up passengers at Belfast International Airport is unacceptable, the Consumer Council has said.
The airport has announced it plans to bring in the charge on 7 July.
It will also only allow motorists to use the new drop off zone for 10 minutes, before they have to park.
The Consumer Council said its research showed over half of all NI air passengers get a lift or take a taxi to and from the airport.
"Based on 2009 air passenger figures the Consumer Council estimates this new charge could generate revenue of up to £2.3m per year for BIA," it said.
"The Consumer Council is also concerned that the new charge may in fact hinder rather than help airport traffic congestion.
"If passengers are to pay a £1 fee to use the drop off/pick up zone, many will drop off on the surrounding roads to avoid the charge.
"This is turn will lead to more congestion outside the airport and further safety concerns as the numbers of passengers with luggage walking to and from the terminal will increase."
SDLP South Antrim MLA Thomas Burns said the airport had taken "a scandalous decision."
"The airport is really sticking the arm in to try and squeeze more money out of travellers to boost their profits at the beginning of the busy holiday period," he added.
The airport said it had invested heavily in the drop-off zone in the wake of new government guidelines after the Glasgow airport bombing.
The minimum distance between the terminal and vehicle zones was raised.
An airport spokesperson said that it had also doubled the time duration at the lowest rate in the short-stay car park for those who needed to stay longer than 10 minutes.