Climate Change Minister Paula Bennett has rejected calls for legislation on emissions targets, saying "we're just not quite there" yet.
Parliamentary Commissioner for the Environment Jan Wright wants targets made into law, and parties to work together so there isn't "chopping and changing, flipping and flopping" every three years.
The UK adopted its legislation in 2008. Its emissions were already declining, and in 2015 were 38 percent below 1990 levels. In contrast, New Zealand's emissions have risen by 64 percent and would likely be even higher if weren't for the impact of the global financial crisis.
"The Government of the day still gets to make decisions, but there's a process put in place that keeps on going," Ms Wright told The AM Show on Friday.
"What you also have there is an independent climate commission which gives its advice freely, openly and publicly - everyone can see it. You're not having advice given to Governments behind closed doors that you have to try and get hold of with the Official Information Act."
Ms Bennett doesn't see the need for legislation however.
"I think we probably will get there one day. We're just not quite there," she told The AM Show. "I don't think the time is right for us to be doing the legislation."
Labour, on the other hand, will.
"We don't have time to sit there and say, 'We'll get there one day.' We're not on track to reach our targets as it is," said Jacinda Ardern, appearing alongside Ms Bennett.
"Even the Young Nats agree with this.. We would legislate those targets - why not?"
Ms Bennett said the UK was achieving its massive reductions by shifting its manufacturing offshore - something she wouldn't enforce on New Zealand's primary sector.