The appeal supported the introduction of Māori seats but questioned the size of the general constituencies, including whether the Ruapehu general constituency was viable given its relatively low population, and whether there should be more seats for urban populations.
Horizons acknowledged concerns that the urban voice might be under-represented but said many of the responsibilities of regional councils focused on rural areas, such as environmental and freshwater management.
The council said it had decided against merging smaller constituencies such as Ruapehu and Tararua with others because it would result in unnatural groups of communities of interest and would not support effective representation.
It said the Ruapehu constituency in particular was a large, remote and isolated part of the region and there were long-established reasons for a separate Ruapehu constituency.
The electoral roll an elector is registered on determines which constituency they can vote in. Electors on the general roll can vote in one of Horizons' general constituencies and electors on the Māori roll can vote in a Māori constituency.
