Franklin District Council has lost its bid to break away from the Auckland supercity.
The area, south of Auckland, applied to become a stand-alone council instead of being split into three with some parts in the supercity's boundaries and some not.
Mayor Mark Ball has received a letter from the Local Government Minister, Rodney Hide, turning down the request.
Mr Hide wrote that he believed a single council would result in cost savings for rate payers.
Mr Ball says he is extremely disappointed by the decision and says it is a "travesty of democracy" that the wishes of Franklin residents have been ignored.
The mayor says the district is unlikely to be able to pursue other means of becoming a separate council.
