Food prices could be next after fuel price crackdown - Jacinda Ardern

Kiwis are paying top dollar at the petrol pump, but many say the price of our food is also inflated. 

Now that fuel companies will be forced into greater transparency, the Prime Minister says supermarkets could be next.

Jacinda Ardern said on Monday the Government would prioritise passing the Commerce Amendment Bill, which will compel the fuel industry to prove it's not engaging in anti-competitive behaviour.

While sky-high petrol prices mean fuel companies will be first under the microscope, the new law could subject more than one industry to increased scrutiny.

On Wednesday, Ms Ardern said Foodstuffs and Countdown - the two monoliths which own all New Zealand's major supermarket chains - could be next.

"Other areas around the cost of living have been raised," she told Stuff.

"Particularly when New Zealanders compare what happens in Australia, Kiwis say, 'Why are we seeing that marked increase here?'

"I wouldn't be surprised if we see a nomination in other areas like that."

Food prices in New Zealand have been a hotly debated topic for some time, with many convinced Kiwi consumers are being charged much more for the same items than our neighbours across the ditch. 

In 2017, Newsroom editor Bernard Hickey told The AM Show Kiwis are "certainly being charged more than Australians", because Foodstuffs and Countdown have a duopoly in our food industry.

He said New Zealand might benefit from a third supermarket chain to maintain healthy competition - Australia has Coles, Woolworths and ALDI, for example - but it's not practical here because our population is too small.

However around the same time Consumer NZ chief executive Sue Chetwin said several factors were to blame for our inflated produce prices.

Foodstuffs Ltd owns New World, Four Square and Pak'nSave, while Countdown Ltd - a subsidiary of Australia's Woolworths Ltd - owns Countdown.