Those who live just above the breadline are likely to be hardest hit by the removal of the ability to sort items by price, on New World and Pak'nSave websites

Consumer NZ is warning shoppers about the change, labelling it bizarre, given the option is available on most retail sites.

Massey University Marketing Professor Bodo Lang says we're trying to make it easier for people to make good grocery decisions.

He says not being able to sort by price seems like a small technicality, but it actually has a big impact on many shoppers.

Consumer NZ says Foodstuffs told them it's upgrading its digital platform to include more transparent unit pricing, and a new sorting feature will be added soon.

Foodstuffs has been approached for comment.