The Greens want a government-owned supermarket — but can't say how much cheaper your groceries would be

The Green Party wants the government to buy into the supermarket business. But it cannot say how much cheaper your groceries would actually be.

The party's plan is called KiwiMart. It would be a government-owned supermarket chain set up to compete with the two big players — Foodstuffs and Woolworths — that currently dominate the grocery market in Aotearoa.

Green co-leader Chlöe Swarbrick said she would not put a number on how much cheaper things could be. "Politicians are not economists," she said. She thinks deciding what counts as unfair pricing should be left to the Commerce Commission, which is the government agency that watches over competition in the market.

The plan involves buying 120 existing stores and two distribution centres at a cost of $2.8 billion. That would create a third supermarket player with about 15 percent of the market. The Parliamentary Library costed the policy at $2.8 billion.

Swarbrick said KiwiMart would not be a charity. After the upfront cost, it would pay its own way. The co-leaders of the Green Party as of September 2026 are Marama Davidson and Chlöe Swarbrick.

The Greens also have a separate plan to ban price gouging — that is, charging unfairly high prices — at New Zealand supermarkets. That plan includes spending more than $100 million to give the Commerce Commission more power, and a rule that shops must automatically pay you back if they overcharge you.

The reason the Greens are pushing this is clear. In June, the two big supermarket companies were reported to hold 82 percent of the New Zealand market, and more than 90 percent in some areas. In 2022, the Commerce Commission found they were making $1 million a day in excess profit. A month before that, the Commission took Foodstuffs South Island to court, saying its behaviour had stopped customers getting cheaper prices.

The problem for the Greens is that their whole pitch is about cheaper groceries, but they cannot say how much you would save. They want to spend $2.8 billion buying existing stores rather than building new ones. That means the government would take on the current stores and supply setups, and hope that a government-owned supermarket run like a normal business would still push prices down enough to matter.

The wider question is whether this approach would actually work. The Greens are trying two things at once: setting up a government-owned supermarket to create competition, and giving the Commerce Commission more power to crack down on the private companies. Both depend on factors the Greens cannot fully control. The Commerce Commission has already tried taking one of the big companies to court, and the duopoly still makes a million dollars a day in excess profit. Whether a government-owned supermarket changes that is what the Greens are asking voters to bet on.