Air New Zealand's domestic airfare cuts are likely to focus on regional flights, but there'll be some discounts on the main trunk as well.

The airline is predicted to announce it's cutting the price of about 40 domestic routes by up to 50 percent.

Aviation commentator Irene King says she expects the scheme will get bums on seats.

"A dramatic slash in airfares will actually shift traffic. It's just the amount of people into the air. It's not that they weren't going, its just the mode that they go by." 

She told Mike Hosking the cuts won't be limited to low-traffic flights connecting the regions.

"The regionals are a particular focus because of the perception that Air New Zealand is gouging the market. But I would think that what they'd be looking at is reapplying their whole pricing structure."