A Christchurch protest group wants an independent investigation into whether earthquake-damaged council buildings had enough insurance.
Councillors on Wednesday voted unanimously on Wednesday to increase rates by 7.5%, of which 2% will cover the repair or replacement of major council facilities.
These include 10 buildings damaged in the February 2011 earthquake.
Cantabrians Unite believes the rates increase may be linked to the under-insurance of council buildings.
The group says central government must appoint an investigative body to look into the council's insurance policies and heads should roll if it is discovered people were negligent in their decision-making.
Christchurch mayor Bob Parker says the insurance will cover what the city already had, but the council will improve and rebuild the facilities to 100% of the Building Code.
Mr Parker says based on the seismic risk before the quakes the council had very good cover in place and is confident its processes will stand up to scrutiny.
The draft annual plan and proposed rates rise will be put out for public consultation.