Labour party leader Jacinda Ardern says there needs to be consistency about how natural resources are treated ahead of an expected water bottling levy announcement.
Ms Ardern told the AM Show that there needs to be remuneration for water used for profit.
"We treat mineral resources as if there was some collective ownership there, in the sense that we give back to the state, and yet there's been a difference in how we treat water," she said.
The Labour Party is set to announce its first major environmental policy on Wednesday, which will include a levy on water bottlers.
While Ms Ardern wouldn't disclose the details of the policy ahead of the announcement, she said they needed to make sure there was consistency about how they charge for water.
There should be an expectation from the public that when people use water for profit there be some remuneration off the back of that, she said.
"What the public is seeing with water bottling companies being able to ship offshore without there being any contribution - any form of levy - unlike any other forms of resource the way we treat other minerals like petroleum is completely different."
"Kiwis have seen that as unfair and for good reason".
Labour is the latest party to support a bottled water levy; the Greens and New Zealand First also support it, but National is opposed.
Environment Minister Nick Smith says the focus must be on the sustainability of the water resource.
On Monday the New Zealand Beverage Council released a report aimed at "bringing balance to the debate", saying unfair targeting of the bottling industry with punitive tariffs will prevent it from creating long-term employment in regional New Zealand.