The "tax haven" status of Inverness Airport has been challenged by rival operators.
People flying to and from the Highland capital have been exempt from paying Air Passenger Duty (APD) since 1994.
Scotland-wide plans to abolish APD were
dropped in May and now Aberdeen Airport is calling for greater parity with its Inverness rival.
Highlands and Islands Airports Ltd said the exemption "must remain in place to protect remote and rural communities".
Extending the APD exemption to Aberdeen or for the tax to be charged on some flights from Inverness have been mooted.
The call comes from the independent consultative committee which advises Aberdeen International Airport.
Long-haul flights
Committee chairman Dr Peter Smart said passengers on a long-haul flight, routed through London Heathrow or Amsterdam, could currently save £78 on a ticket by flying through Inverness instead of Aberdeen, 92 miles away.
He said: "What we're seeking is action from government to ensure that Aberdeen and Inverness are treated identically.
"It's for government to decide how but the two options seem to us to be either exemption for flights from Aberdeen or levying APD on flights from Inverness to destinations outside the highlands and islands area.
"It's about time Inverness is required to operate just like any other airport of its size, on a commercial basis.
"What might have been appropriate a few years ago, when its passenger numbers were less than half a million, cannot, we feel, be justified now.
Dr Smart said that separate public subsidies for a route out of Dundee Airport meant, "one might compare Aberdeen to a highly taxed island sitting between two tax havens".