Opponents have vowed to fight Transpower's proposed 400kV transmission line across the Waikato if the company gets approval from the Electricity Commission.
The warning came at the end of a week of public meetings hosted by the commission to explain its progress in assessing alternatives to the $500 million pylonplan.
Transpower says the 190km line is needed to prevent blackouts in Auckland and Northland by 2010.
Anti-pylon lobby group New Era Energy spokesman Bob McQueen said commission chairman Roy Hemmingway appeared genuine in his investigation into alternatives, but the group was determined to stop the massive pylons -- up to 70m high -- and had been fundraising since October to pay for court action.
"It's going to be a lot of money but we have a fairly big war chest," Mr McQueen said.
On Tuesday, Waipa councillors voted to use the Resource Management Act process to object to the pylons if necessary.
Transpower is expected to lodge a resource consent application if it gets the commission's backing, which would require councils to publicly notify the proposal and call for submissions.
Waipa Mayor Alan Livingston said Transpower's preferred western route cut through Lake Karapiro -- protected under the district plan as a "special landscape character area".
The area covers river terraces around the lake and the slopes of Maungatautari.
He was "gutted" Transpower seemed happy to ignore public opinion and proposed to destroy a stunning natural environment.
The council wanted Transpower to revert to its previously proposed eastern route to avoid Karapiro. If that was not possible the line should be put underground through that landscape.
The council had retained Wellington-based QC Bill Wilson to head its fight. Mr Livingston would not put a price on this.
Transpower spokesman Chris Roberts accused the Waipa council of jumping the gun.
"They can be an advocate on behalf of their ratepayers but they have to run an impartial resource consent process."
This week Mighty River Power told Transpower the mothballed Marsden B coal plant in Whangarei -- which has just received resource consent to fire up -- could supply enough power to delay the pylons for three years.
