The Alliance Party is questioning whether Foodstuffs affiliated supermarkets can offer lower prices because of inferior wages and conditions for distribution workers, as industrial action hits their outlets.

Alliance Party co-leader Kay Murray says it is interesting to note that Foodstuffs affiliated supermarkets overall have cheaper prices than Progressive enterprise affiliated supermarkets, according to the latest Consumer NZ annual supermarket survey.

This will no doubt lead to many shoppers changing where they supermarket shop in order to get a better deal on their groceries.

But Ms Murray says it is perhaps time for Consumer to delve a little deeper with their study and examine why Foodstuffs is able to offer cheaper groceries.

"If it is because the Foodstuffs Co-operative is prepared to take a lower overall profit for its stakeholders so that consumers can benefit from cheaper food, then they should be given credit. However if it is simply because their workers have to accept worse wages and working conditions then this should be pointed out so that consumers can make an informed choice as to where they do their grocery shopping."

Ms Murray says it is a matter for concern that even as the results are announced the Foodstuffs distribution centre workers are in the midst of industrial action because of the low wages they receive.

According to the National Distribution Union, "Foodstuffs distribution centre workers' low weekly wage is totally unjustified given the company's dominance and profitability in the supermarket industry - of which they control 57%. Foodstuffs' main competitor Progressive Enterprises pays a start rate of $5 more per hour for distribution centre workers doing the same work."