An airline group is casting doubt on demand for sending long-haul flights into Wellington Airport.

The Airport's announced a $500 million five-year upgrade plan – which includes extending its runway.

It will let bigger planes land – with hopes it'll attract non-stop flights from Asia and Los Angeles.

Board of Airline Representatives chair Cath O'Brien told Heather du Plessis-Allan it costs a lot to fly to New Zealand.

“If I look at air services demand for New Zealand in total, I don’t see any real growth at the moment. So, Auckland Airport is looking at pretty much a flat scenario.”

LISTEN ABOVE