The government should scrap the $1 billion four-lane highway from Warkworth to Wellsford instead of crying poverty and cutting services in the budget, the Greens say.
They call it "the holiday highway" and transport spokeswoman Julie Anne Genter says she's got new information which puts its economic benefit at $620 million.
NZ Transport Agency data also shows traffic volumes on the route are stagnant, she says.
Ms Genter is also citing an International Monetary Fund paper released last week which says oil prices will double by the end of the decade.
"We will be paying $5 a litre in a decade's time, well before this highway would be completed," she said on Thursday.
Finance Minister Bill English will deliver a zero budget next Thursday and "new money" for education and health will have to come from savings in other areas.