The Eden Park Redevelopment Board says it is aggressively seeking sponsorship to fill a $40 million shortfall for redeveloping the Rugby World Cup venue.
But its chairman, John Waller, says last year's market made it difficult to secure sponsorship and the board is looking at other ways to complete the project.
The Government has told the park's redevelopment board it won't increase its $190 million contribution and councils must guarantee the gap while they seek commercial sponsorship.
Eden Park is the venue for the 2011 Rugby World Cup final. The revamp is due to be finished on time in October.
Rugby World Cup Minister Murray McCully says councils have been slow to line up because of Auckland City Council's insistence that it will not contribute cash to the project.
He says talks are under way and he hopes the councils can agree within weeks to underwrite the gap.
However, Eden/Albert ward member Mark Donnelly says the problem with underwriting the project is that it would be like writing a blank cheque, forcing the council to bankroll the park forever. He says it would be money lost on a white elephant.
Mr Donnelly says government ministers foisted a Wellington project on Auckland so they should fund it themselves.
But Manukau Mayor Len Brown says Auckland's leaders must get behind the $40 million guarantee. Mr Brown says that if the underwriting is ever called upon, it would be on a commercial basis and would be paid back to ratepayers.