As well as writing to the commission demanding the information be retracted, and complaining to the Office of the Auditor-General, the council has taken out a full-page advertisement in today's Hawke's Bay Today repeating its claim that figures in the reports are inaccurate by just under $1 billion.
In yesterday's letter to commission chief executive Sandra Preston, NCC chief executive Wayne Jack said if the amalgamation process was not put on hold, and corrected financial details published, the council would take steps "to demonstrate the clear bias evident in the attempts to mislead and misinform the communities of Hawke's Bay".
In its 133-page report for the commission, consulting firm MWH New Zealand admitted there were some "quite significant inconsistencies" in the financial information it collected from and about the region's councils, but that it was not material to the firm's overall findings.
"A more comprehensive exercise may change the degree of some of the conclusions reached but not the overall picture," the firm's report said.
Mr Jack said, in his letter yesterday, that assertion was "unsustainable" given the size of the difference in the value of council assets between the figures relied on by the commission and those calculated by the council.
According to the commission, NCC would have to spend all of its $78 million of financial reserves, plus a further $45 million, to bring its roading and water system assets up to the average standard of councils across Hawke's Bay.
But according to the council's figures, its infrastructure is worth $69 million above the regional average.
In today's advertisement, the council says it wants to "reassure" ratepayers that the city's roads and water networks are in good condition, and it says that was verified by an independent study it commissioned last year.