What can bring on a by-election? Tāmaki Makaurau?

By-elections in Aotearoa are rare events but on the odd occasion they do happen. By-elections happen for a raft of reasons such as a sitting MP retires (this most notably happens after a sitting Government loses the election but the MP wins their sit but opts not to sit in Opposition) and on the very rarer occasion an MP passes away while in office. In November of 2023 a by-election was called on in the seat of Port Waikato with the death of ACT candidate Neil Christensen during the general election campaign. National’s Andrew Bayly retained the seat with a commanding 76% of votes, defeating NZ First’s Casey Costello (15%). With Bayly already a list MP, his electorate win allowed National to bring in an additional list MP, Nancy Lu.

Then there was the resignation (2022) of Independent MP Gaurav Sharma, who was expelled from Labour. National’s Tama Potaka won 46% of the vote, with Labour’s Georgie Dansey trailing at 30%. Of course Potaka went on to become the Minister of Maori Development. With the resignation of former National leader Simon Bridges (2022) Tauranga went to a by-election. National’s Sam Uffindell won decisively with 56% of the vote, while Labour’s Jan Tinetti secured 25%. A by-election was triggered in the National held seat of Nortcote in 2018 after the resignation of National MP Jonathan Coleman. Dan Bidois would win (just). Bidois held the seat with 51% over Labour’s Shanan Halbert, capturing 44%. The seat would turn at the General Election in 2020 to Labours Halbert but back again to Bidois in 2023.

In the Māori electorates the first by-election can be traced back to Western Māori  in 1893. Te Puke Te Ao passed away with the seat going on to be won by Henare Kaihau. In 1930 Āpirana Ngata came into the seat of Eastern Māori – a by-election triggered by the passing of Sir James Carroll. Aotearoa got one of the most influential Māori politicians of the 20th century. On the death of Tāpihana Paikea (Northern Maori ) in 1963 Labours Matiu Rata would come to office. Rata was born in the Far North settlement of Te Hāpua – Returning to New Zealand from merchant marine service in 1954, Rata worked in a variety of jobs, including as a spray painter at the Ōtāhuhu Railway Workshops from 1960 to 1963. Of course The Treaty of Waitangi Act 1975 was to be Rata’s legacy. When Rata resigned from the Labour Party the seat went to a by-election and was won by Dr Bruce Gregory (Labour). Tau Henare won the electorate from Gregory for New Zealand First in 1993. Tau Henare is a great-grandson of Taurekareka Henare who had held the electorate for the Reform Party from 1914 to 1938. In 2013 Ikaroa-Rāwhiti went to a by-election after the passing of Parekura Horomia two months earlier, who had represented the electorate for the Labour Party since its inception for the 1999 election. 

With the passing of  Te Pāti Māori MP Takutai Tarsh Kemp a by-election is now triggered in the seat of Tamaki Makaurau. Though a date is yet to be set for the by-election it is likely to be held by the end of August 2025.

“Once the Registrar of Birth and Deaths receives the registration of death for a sitting MP, they must inform the Speaker of the House within 12 hours, and then the Speaker must publish, without delay, the notice of vacancy of the seat in the New Zealand Gazette. The governor-general must issue the writ for a by-election to fill a vacant electorate seat within 21 days of the gazette notice.”

By-elections are not held in seats where List MPs are involved, they are normally replaced by the next person on the Parties list. When NZ First MP resigned on 27 June 2025 she was replaced by the next person on the list, David Wilson.

More to come