The Rotorua Pro-Democracy Society has decided not to pursue legal action to challenge the Te Arawa Partnership Plan.
In May, the Rotorua Lakes Council adopted the proposal to give Te Arawa representatives voting rights on to the council's two key committees.
The Pro-Democracy Society has previously questioned the legality of the plan, but at a meeting last week up to 50 members unanimously voted against seeking a judicial review of it, society secretary Reynold Macpherson said.
The council had been advised by Hamilton-based law firm Tompkins Wake in April the proposal was "lawful and compliant".
The council's strategy and partnerships group manager Jean-Paul Gaston told the Rotorua Daily Post yesterday they stood by that opinion.
"Rotorua Lakes Council has always been and remains confident in the legal advice provided by Tompkins Wake prior to and during the Te Arawa Partnership Model proposal and hearings."
But Mr Macpherson said the society had been advised by a "leading national legal authority" Dr Andrew Butler that the partnership plan was illegal. They also sought legal advice from law firm Russell McVeagh, which they provided to council chief executive Geoff Williams on April 20. That advice concluded there was "a real issue" with the legality of the partnership model, which could lead to a successful judicial review of the council's actions.
Mr Macpherson said legal fees and court costs of a judicial review could reach $100,000. If all costs were to be awarded against the council, the ratepayers would have to pay, he said.
"The main reason was that we didn't want to put any costs on the community even if we were to win, the council could implement the ruling by rescinding its Te Arawa
Partnership Plan decisions, and then use existing powers to co-opt the same nominees back on to its committees. Mounting a judicial review and awaiting a result could take most of a year, by which time council elections would soon be due."
The society committee would continue to meet and plan how to "achieve democratic and effective local government that recognises the diversity of our community" with a change of council in the 2016 election, he said.
"We would be looking to promote an alternative mayoral candidate and a ticket of candidates who share our views."