Money has poured in to help the Mangawhai Ratepayers and Residents' Association question the legality of Kaipara District Council rates in the High Court.
An appeal last week for $50,000 needed to take the case to court brought a quick response from the association's 500 member households who had been asked to each contribute $100 if they were able to.
"We are already 90 per cent of the way there," association chairman Bruce Rogan said on Monday.
"Thousands of dollars just poured in to our fighting fund from grassroots ratepayers. We haven't had to go back to potentially big contributors who had indicated they would chip in more if required."
The association - which has led a strike against paying Kaipara rates - appealed for financial support after its Auckland barrister, Kip Littlejohn, finalised his legal opinion accusing the council of acting illegally when setting rates this year and saying the court was likely to reverse council rating decisions.
"If this opinion is supported by the court, all penalties the council has tried to apply will be cancelled and they will have to refund rates paid this year," says a message posted on the association website last week.
"They are also likely to have to refund many rates payments from preceding years and also repay any penalties they have applied."
The owners of about 1100 Kaipara properties - more than half of them in Mangawhai - have not paid their 2012/13 rates. And of the owners of the remaining 12,812 properties in the district, about 2600 have only part-paid their rates.
Increases which have more than doubled some rates were set by the former council in a bid to deal with an $80 million debt mostly attributable to the Mangawhai sewerage scheme.
Although the previous council admitted some of its rates and fees had been imposed illegally, the four Government-appointed commissioners who had been governing the district for the past three months had instructions from Local Government Minister David Carter to enforce the rates.
The commissioners' chairman, John Robertson, last week said Parliament was likely to be asked to validate a "dog's breakfast of procedural and technical failings" in the Kaipara rates.