The Auckland Council has supported the Government fast-tracking approval for the disputed Puhoi to Warkworth Highway.
The council agrees the section of State Highway 1 is a Road of National Signficance and should go to a government-appointed board of inquiry to deliberate.
The council previously agreed to the project in principle and a clear majority on Thursday gave the nod to fast-tracking the process if the Government proceeds.
Left-leaning councillors Mike Lee and Sandra Coney argued against it, describing the proposed new section as a political project without a proven need.
The New Zealand Transport Agency has told the council that funding is not yet certain and construction would not begin for several years.
The 18km highway section would cost about $750 million.