The Green Party co-leader Marama Davidson says New Zealand is open for corruption under the current rules around political donations.
Prime Minister Jacinda Ardern said she wants to hear from New Zealanders around issues with donations but believed the current system is robust.
But Ms Davidson said under current rules donors can corrupt the political system.
She told Morning Report powerful businesses can gain influence with large donations.
"I think New Zealanders would be quite keen on a conversation on how we get big money out of politics," she said.
"What we've seen around the world is that those with particular interests can have millions or hundreds of thousands of dollars worth of influence on political policy.
"For example, a global pattern around 'Big Oil' getting their big money into politics and influencing action on climate change."
Ms Davidson said the Green Party is suggesting a cap on donations at $35,000 and to remove anonymity for any donation above $1000.
"We've already seen a $100,000 donation to the National Party being questioned, from someone who is a powerful businessman.
"I want to see equal access and not just big money having undue influence over our political system."
She said a cap on donations would give Kiwis more confidence in the political system.
"Even within the current laws there are loopholes. You can hide donors here and there, and I think that's something we need to clean up."
"New Zealanders are starting to understand we could go down a slippery slope here," she said.
She said people could still split donations under a $1000 cap, but it would be much more arduous than the current system.
"I think it would be quite off-putting to those large money donors, and that's what we're really looking for here.
However, she said ruling out anonymous donations all together would be a mistake.
"It's understanding that the bucket in the pub - $20 here $50 there - still allowing that without having to add unnecessary bureaucracy."