The National Party says it is "unacceptable" for the government to push ahead with its three waters reforms without a serious audit of its plans for debt financing.
Both National and Act say the proposed new structure, which would have the management of drinking, waste and storm water overseen by four new independent entities instead of the councils, lacks financial coherence.
The Opposition wants to know how such an arrangement will raising enough capital to fund infrastructure improvements in areas such as new drinking water quality standards.
National's local government spokesperson Simon Watts spoke to Corin Dann.
