Ms Calvert — also an ex-Otago regional councillor and Act MP — has filed a statement of claim with the High Court in Dunedin along with her husband Alastair Broad, their daughter and son-in-law.
They are claiming more than $155,000 in damages and financial losses over the dispute, in which they said the council had been "unlawfully using its power to extort property rights from a ratepayer" to avoid liability for a historical error of its own making.
The dispute centres on an access road to a neighbouring Inverlair Lodge, part of which was formed across a corner of their land about 15 years ago.
In 2021, the couple were granted consent to subdivide the land to create a new allotment for their daughter and son-in-law, Julie and Hamish Mander, to build a house on.
However, in June last year, after the council discovered the access road to Inverlair Lodge was non-complying, a staff member told them they would first have to allow an easement across their land to give the lodge’s owners legal access.
In their statement of claim, the couples said the subdivision consent had no relevance to the lodge’s access issue, and the council staff member made a "false representation".
The staff member — who no longer works for the council — also threatened to tell Inverlair Lodge’s owners the couple would block access to the property.
The couples said they never considered blocking access, which would have "significantly harmed personal relationships and caused considerable ill will in the neighbourhood".
The council’s refusal to sign off the subdivision or accept the Manders’ building consent application in June was unlawful, a "deliberate disregard" of its public duties, and aimed to pressure them into providing the right of way.
The council was motivated by a desire to avoid the considerable cost of building legal road access to Inverlair Lodge.
With building prices increasing rapidly and any further delay in getting building consent likely to significantly increase the cost of building the house, Ms Calvert and Mr Broad made the "unpalatable choice" of agreeing to the easement in July.
The subdivision was duly signed off and the building consent issued the following month.
The couple then presented two legal opinions to the council arguing it had acted unlawfully and owed them compensation, but they were not referred to the council’s lawyer.
Ms Calvert told the Otago Daily Times they had taken the matter to court because they were concerned about the council’s behaviour, and wanted compensation for the costs they had incurred.
Councils held a special position in society because they were "regulatory and monopolistic", and such power had to be wielded with care.
"I feel strongly that in this case, that power was not used in a way that was proper."
A council spokeswoman said it would not comment on the case as it was before the court.