Labour leader Andrew Little is not supporting the admission by Green's co-leader Metiria Turei that she will not condemn struggling beneficiaries who lie to WINZ.
Talking to 1 NEWS political journalist Katie Bradford, Mr Little said despite the reason many politicians aspire to govern is to change current laws, "we can never condone breaking the rules".
"In the end, as lawmakers, as politicians, we are here because we want to set the rules.
"Whether or not we like the rules of the benefit system, they are the rules at the moment," he said.
"You get to change the rules when you're in government. I think we've got to be focused on what we can do."
Ms Turei confessed this month she sub-let her home and lied to social services as a single mum claiming benefits in the 90s.
"Metiria is a good leader, she's struck a nerve," Mr Little said.
"But once the rules are set, that is what we've got and we cannot be seen to be condoning breaking the rules because that gets us down a very slippery slope that will create all sorts of problems."
When asked by Jack Tame this morning on TVNZ1's Breakfast this morning if she condones those people breaking the law she said, "I don't condemn these people for doing what I did".
"I'm not interested in judging these individual parents. I want to fix the system that forces them into these terrible, awful choices.
"My job as a law maker is to make sure that every law in this country is fair, and just, and does not punish people unnecessary simply because they're poor."