The New Zealand Vegetable Council is calling for more transparency across the supply chain so consumers know what they are paying for.

The ongoing cost of living, particularly rising food prices for products in shoppers' baskets, has seen food security and the supermarket duopoly emerge as a key election issue this year.

National says if re-elected on November 7, it would split up the Kiwi-owned Foodstuffs (New World, Pak‘nSave and Four Square chains) - although only after the Commerce Commission investigated to make sure it would benefit consumers.

Meanwhile, Labour has promised to tackle price gouging and the Greens have proposed breaking up the supermarket duopoly by setting up a publicly owned 'KiwiMart'.

NZVeg chief executive Mike Brown said growers were already operating under tight margins and about half their growers did not know if they would be around in 10 years' time.

"If growers cannot make a responsible profit they will go out of business, which will reduce supply and increase the price to the consumer," he said.

"While we applaud the opportunity to address the cost of living for consumers, in actuality veggies haven't been as inflationary as other items in the shopping basket.

"So that points to growers actually operating on very slim margins within the supermarkets."

Veggie growing was a risky business as it was vulnerable to bad weather, he said.

"As we saw with Cyclone Gabrielle, shortages and price rises result when a vegetable growing region is affected by an adverse weather event."

Other challenges impacting the industry included energy prices, regulations and repealing the Resource Management Act, urban expansion into productive land, and competition with cheaper imported food.

Brown said another emerging challenge was access to gene-edited seed - after the European Parliament recently passed regulation to allow gene-edited plants that do not introduce foreign DNA.

"What that will mean is seed suppliers offshore will be focusing on EU needs and we'll really be left off ... the import map for seed. So we really have to have some good consideration about changing the settings to allow us access to that seed that will be necessary for our growers to remain viable."

NZVeg was also calling for a bi-partisan, national approach to vegetable production in resource management reform to help address food security issues.