The Green Party is pushing for a tourism tax to pay for much-needed regional infrastructure and the government's predator-free plan.
The Taonga Levy - which would cost between $14 and $18 - would be added to existing border charges for international visitors.
Green Party co-leader James Shaw said international visitor numbers were expected to reach 4.5 million in the next six years.
A $14-18 levy would bring in more than $60m a year, he said.
Predator-Free New Zealand would get about $46m and the Regional Tourism Facilities Fund $20m, under the Greens' plan.
"The Taonga Levy will bring in tens of millions of dollars every year to help make New Zealand's dream of being predator-free a reality, and help tourism hotspots cope with rising visitor numbers.
"The government has failed to back up its glitzy predator-free promise with the money to get the job done. The Taonga Levy will help make it actually happen," he said.
Labour leader Andrew Little said a tourist tax was a good idea in principle.
"I'd like to see a properly structured levy being used for things like Predator-Free New Zealand, as well as ensuring we have good tourist facilities, especially in the regions that are struggling to cope with growing tourist numbers and a bit of supplementary income for the [department of conservation]."
But Conservation Minister Maggie Barry said the charge would turn tourists away.
Tourism was a huge earner for the country, she said.
"We don't want to kill the goose that lays the golden egg.
"They are looking at doubling the amount of money visitors would pay to come to New Zealand. I think that could actually be a real discouragement," Ms Barry said.
However, Tourism Minister - and Prime Minister - John Key was a little more open to the idea, and said the private sector was looking at a tourist levy for the government.
Mr Shaw said a $14-18 tax was not a big cost.
"It's still a lot lower than both Australia's border levy and also that of the United Kingdom."
The Taonga Levy, once combined with the existing border clearance levies, would bring total levies paid by international visitors to approximately $40.
Australia charges a $NZ58 boarder charge, while the UK charges $NZ127.