New Conservation Minister Eugenie Sage says the Predator Free 2050 goal needs a "reality check".
The ambitious plan was announced by former Prime Minister John Key last year, but Ms Sage says it lacks a plan and funding commitment.
Roughly $70 million is spent each year on predator control throughout New Zealand.
The National government gave $28 million to set up an organisation to manage the programme and promised a dollar for every $2000 donated by the private sector.
Ms Sage says that's not enough.
"There wasn't a clear and detailed plan about actually how to get there, and there wasn't the funding commitment," she told Newshub.
But former Conservation Minister Maggie Barry says it's her successor who lacks commitment.
"Why does this new minister get to come in and tell them they're on the wrong track?" she said. "She needs to explain and commit."
Wellington pest-killer Paul Ward says the Predator Free 2050 goal has served a purpose.
"It's been a goal that's coalesced a lot of energy around looking after our manu mates in our backyard," he said.
This week, Predator Free 2050 unveiled its research strategy, which included investigating genetically engineered rats to produce only male offspring and fine-tuning the approach to killing possums.
"It sounds to me that she doesn't know very much about it and she's just dismissing it for political reasons," Ms Barry said. "That's that 'extreme green' thing."
Forest and Bird boss Kevin Hague says the Minister is right to be worried about the goal.
"The funding level is clearly inadequate to get anywhere near that goal."
The Government has promised the Greens that the Department of Conservation will get a "significant increase" in funding, but the Conservation Minister can't give a figure.
Like everyone, she has to wait for next year's Budget.