Since the , the number of electorates in the South Island was fixed at 25, with continued faster population growth in the North Island leading to an increase in the number of general electorates. There were 84 electorates for the 1969 election, and the 1972 electoral redistribution saw three additional general seats created for the North Island, bringing the total number of electorates to 87. Together with increased urbanisation in Christchurch and Nelson, the changes proved very disruptive to existing electorates. In the South Island, three electorates were abolished, and three electorates were newly created. In the North Island, five electorates were abolished, two electorates were recreated (including Coromandel), and six electorates were newly created.