Auckland International Airport yesterday asked the Government to take a closer look at foreshore veto rights which it says could put future expansion at risk.

Corporate general manager Charles Spillane addressed the Maori affairs select committee about the impact the Government's Marine and Coastal Area Bill could have on the airport, which contributes $19 billion to the national economy.

Key airport infrastructure at Manukau Harbour had been built in the short term but the completion of the second runway was still to be ticked off, as were crossings of waterways for roads servicing the airport, pipelines and a new fuel storage facility.

The airport has concerns about permission rights which coastal iwi or hapu gain if they succeed in obtaining customary title - a form of ownership - over wet sand to the 12-mile limit.

Permission rights allow title holders to veto or approve proposed development requiring resource consent with some exceptions.

Mr Spillane said the airport's problem was that the test for obtaining "accommodated activity" status, which would allow the permission right to be waived, was of an unduly high standard. That's because the work had to be "essential".

"It does not appropriately balance iwi and conservation interests with the importance of ensuring that such infrastructure items can be provided for."

Speaking after the hearing, Attorney-General Christopher Finlayson said he did not accept the airport's interests weren't fairly recognised under the legislation.

Asked if the airport would qualify for accommodated activity status, Mr Finlayson said circumstances would depend "on the facts at the time. [But] we had that discussion with that sort of infrastructure company in mind".

Green Party MP David Clendon asked Mr Spillane to describe the relationship with Manukau iwi as there was the potential for the airport to negotiate many of the matters raised.

Mr Spillane said it still had a way to go. "The relationship ... is something we're working on. There have been issues over the years most recently with the work on the northern runway."

Two years ago koiwi, skeletal remains were discovered during the construction process. Differing marae were unhappy with aspects of the way more than 80 remains were dealt with by the airport and some leaders wanted a longer conversation on the land use because of the koiwi find.

However, the remains had recently been returned to Pukaki Marae.

Mr Spillane said he hoped that was evidence of the first steps towards improving relations.

The committee continues hearing submissions in Auckland today and tomorrow.