Relations between the mining industry and state agencies have slipped to a new low.
Row over EPA bill
Chatham Rock Phosphate is threatening legal action against a branch of the Ministry of Business, Innovation and Employment, and has criticised the Environmental Protection Authority.
Two months ago, the company lost its bid to mine the ocean floor off the lower South Island.
It now faces a bill under the Environmental Protection Authority's cost recovery scheme for $605,000.
Chatham Rock said it never wrote a blank cheque to the EPA for costs, and accused the authority of what it describes as a lack of financial discipline.
It said attempts to debate the bill would only incur fresh costs.
This latest dispute followed an attack on the EPA by mining groups, with its head Rob Forlong saying he sometimes felt guilty about the level of fees he has to charge.