Hapu spokesman Buddy Mikaere said in the objection that Ngai Tamarawaho had lost most of its land following the confiscations of the 1860s.
"Any public land that is surplus to Crown or council needs is, therefore, important to us as another potential acquisition towards the restoration of the hapu estate.''
Mr Mikaere said he understood the council's motivation in wanting to revoke the reserve status of the property to enable a more permanent arrangement for Plunket.
"Our preference is for the reserve status to remain in place," Mr Mikaere said in a letter.
Mr Mikaere told councillors that revoking the reserve status needed the hapu's consent. "This is something we only learned about recently."
Councillor Steve Morris said Ngai Tamarawaho had been incredibly generous in foregoing full compensation for land lost and making it a gift to the people of New Zealand. He then asked why the council was discussing this when the Treaty settlement meant there were no further obligations on the Crown for wrongdoing.
"Why do we keep having this conversation."
Mr Mikaere said they were not trying to make some commercial deal out of the objection. It was only about recognising the hapu's mana whenua (authority) over the land.
Councillor Gail McIntosh and Mayor Greg Brownless supported selling to Plunket, with eight of the other nine councillors supporting the objection. Councillor Kelvin Clout declared an interest and withdrew from the meeting.
Mr Morris said the council needed to take a longer view on the 531sq m reserve because losing reserves reduced the scope for intensification.
Councillor Larry Baldock said once the land was gone, it was gone, and he supported the hapu's aspiration to recover whatever land it could.
Councillor Rick Curach said the council would find a way to allow Plunket to continue to operate on the site and provide security of tenure.
Mr Brownless was critical that a child care centre that received Government subsidies was paying a peppercorn lease of $250 a year to the council.
"Ratepayers need to get some return on this. I thought this [selling] would be an ideal way forward."
Ms McIntosh said the settlement with the Crown was not the council's problem and ratepayers will not thank the council for feeling guilty.