The Wanganui District Council claims that the owner of the city's port lease is trying to sell the contract for many times more than it paid for it.
River City Port Ltd denies the accusation, saying it had plans to improve ageing infrastructure ignored by the council. It has filed papers in the High Court to prevent the council from cancelling its lease.
Wanganui Mayor Michael Laws says the company wants $14 million for the lease when it paid just $1 million in 2004.
He says tabling a local parliamentary bill to effectively end the lease is the only way the council can stop the company from running the port further into the ground, threatening jobs and blocking redevelopment.