Judith Collins says big supermarket chains got an advantage over butchers and smaller grocers during New Zealand's Covid-19 lockdown.
Today, the Government acted on Labour's election campaign promise to launch a Commerce Commission review into prices New Zealanders are paying at the checkout.
However, this morning the National leader told media at Parliament, "I would've thought that one of the things that the Government could do is to address why it gave the big supermarket chains such an advantage during the lockdowns and cut out any competition from smaller business owners such as butchers and green grocers".
Collins also said people in many cases would be finding it "very hard" to foot the bill at the checkout.
"My family found that during the first lockdown that the quality in terms of what was on offer didn't seem to meet the prices that were being asked for and I actually thought it was an extraordinary situation where people were paying very high prices.
"People aren't foolish. They do understand that prices keep going up."
Also speaking to media, Prime Minister Jacinda Ardern said there was "good cause" to review supermarket prices.
"We do have a heavy concentration amongst a couple of big players and that in our mind is good cause for us to look at whether or not New Zealanders are being treated fairly."
She said when Kiwis were able to travel across the ditch, there was "significant price differentials there".
"That's just one thing that led us to believe that it was only right we look at whether or not New Zealanders are being treated fairly, particularly given we have real dominance in our market.
"We also worried about suppliers," she added. "You often hear stories of them not feeling like they are being treated fairly. This allows us once and for all to give some confidence to consumers that both them and our producers are getting a fair deal."
When asked if she can guarantee prices would come down, Ardern said Government would act on whatever the Commerce Commission presents.
"We do have levers. The Commerce Commission, we've given them extra powers to really go in and properly investigate behaviours. We did it with fuel, now we're doing it with our supermarkets and we will act on what they find."