The Court of Appeal has reserved its decision in a case relating to a proposed new stadium for Dunedin.
However, lawyers for Dunedin City Council have told the court that if further consultation is ordered, it will kill the $198 million project.
In April this year, the group Stop the Stadium unsuccessfully sought a High Court injunction, claiming that changes to the project's financial structure would increase costs for Dunedin ratepayers.
Its lawyer told the Court of Appeal in Wellington on Tuesday that the stadium's construction cost was significantly more than the figure earlier included in the community plan put out for public consultation.
However, the council's lawyer said timing was critical in deciding to go ahead with the stadium project - and the price was affected by many things, including changes in interest rates.
He said highly-qualified staff made reasonable predictions about such matters, but if they were required to set everything in concrete it would paralyse the running of local government.
Council pays $7m for Carisbrook
Dunedin City Council has bought hallowed southern rugby ground Carisbrook for $7 million.
The deal was struck by the council and the Otago Rugby Football Union and includes a $2 million loan repayment in return for a three-year lease.
Dunedin Mayor Peter Chin says the agreement represents a sound investment, based on a rigorous independent valuation.
But critics argue the deal bails out the rugby union to ensure it becomes a reliable user of a new stadium being built in the city.
Stop the Stadium president Bev Butler says it appears the council and the union are now "joined at the hip".