Labour is promising to review supermarket and building supply prices if re-elected, to ensure New Zealanders are not paying too much for their groceries and house-building materials.
Labour Leader Jacinda Ardern said her party would launch market studies that would "have the potential to help, by providing us the information we need to act" to bring prices down if needed.
She said the studies would give answers over concerns that New Zealanders are paying more than they should for groceries.
"Groceries are one of our most regular expenses, and buying or renovating a home is the biggest investment many of us will make in our lifetime, so we want to make sure pricing is fair," Ardern said.
Consumer Affairs spokesperson Kris Faafoi said there was a belief New Zealand was becoming less affordable.
"The information collected from these market studies will allow us to put in place any necessary regulatory and policy solutions that ensure consumers are paying a fair price, that innovation in the market is not stifled, and that access and competition are appropriate."
"Good housing underpins a range of social, economic and health outcomes and we need to ensure that Kiwis have access to affordable and fairly priced housing and building supplies."
Labour would launch the study into supermarkets this year and into building supplies next year.
In Government, Ardern launched a market study into fuel prices in December, 2018.
A year-long study by the Commerce Commission found New Zealanders are paying too much for petrol.
The Fuel Industry Bill to change wholesale fuel market arrangements came into force last month.