Labour MP Phil Twyford says New Zealand's largest native tree - the kauri - could be extinct within decades.
The trees are being killed by kauri dieback disease, and while the Government's spent millions trying to find a cure, that funding now looks under threat.
Dr Nick Waipara of the Auckland Council says the fungal disease first attacks the roots of kauri trees.
“It infects through the roots first, rots through the root system, comes to the trunk and then starts to infect the whole trunk of the tree.”
And while the Ministry for Primary Industries has budgeted $4.8 million until the middle of next year to help fight the disease, it says that after that it won't seek further funding from Cabinet.
The ministry says it will find funding from its existing budget, but won't say how much.
Labour says that proves the Government isn't taking the problem seriously enough.
“The kauri is a treasured part of our heritage, our history, our culture. I think if New Zealanders knew that the Government was nickel-and-diming this vital scientific work, they'd be horrified,” says Mr Twyford.
Eleven percent of kauri trees in the Waitakere Ranges have already been wiped out by this disease. But University of Auckland researcher Luitgard Schwendenmann says it's not just the trees that are at stake, it’s the entire forest ecosystem.
“The neighbouring trees, the soil, the water cycle is impacted by the dying trees,” she says.
Mr Twyford says he'll be walking the Waitakere Ranges next week to help raise awareness of the disease, and to put pressure on the Government to continue the fight against it.