The Green Party isn't happy with a government trial which sees beneficiaries given My Food Bags instead of emergency food grants.
More than 700 boxes have been delivered in the trial, which aims to see whether the meal kits could be good alternative to emergency grants.
Green Party Co-Leader Marama Davidson said there is a concern that beneficiaries are not getting a choice in the matter, and that it hides the fact that people simply don't have enough income.
"Everyone should be able to have enough income from the starting point without having to be coerced in how they buy their food," Ms Davidson said.
Social Development Minister Carmel Sepuloni said she was "comfortable" with the trial, and that "it's optional - so no one's being forced to do it."
However, Food Researcher Rebekah Graham says the timing of the experiment was suspect.
"I think it's really interesting that WINZ or MSD have performed this experiment on a group that are really vulnerable and who aren't in a position necessarily to refuse."
And beneficiary Gail Watkins said she definitely wasn't given a choice between a grant and a meal kit.
"They just said 'you're getting bargain boxes' and they promised me I was going to love it."
Criticism of the trial comes as the Greens grow increasingly frustrated at the lack of movement in boosting welfare payments and getting rid of tough sanctions on beneficiaries - something they were guaranteed as part of their confidence and supply agreement.
The My Food Bag trial will pause over the Christmas break and finish early next year and a decision will then be made on whether to roll it out permanently.