Wellington City Council officials are recommending support for a planned $2.4 billion upgrade of State Highway 1 in the capital.
An extraordinary meeting will be held on Wednesday for city councillors to decide where they stand on the project, which includes duplicating the Terrace and Mount Victoria tunnels, and a flyover near the Basin Reserve cricket ground.
The Transport Agency has sought clarification of the council's position, after comments by Mayor Celia Wade-Brown indicated it would only support feasibility studies.
Ms Wade-Brown has written to the agency, confirming council support, and Deputy Mayor Ian McKinnon says he would be surprised if councillors vote against that at the meeting.
However, Councillor Helene Ritchie says more details are needed and she wants the public to be consulted on all options.
