She first worked at a freezing works before obtaining a master's degree in education from Victoria University of Wellington. In both softball and netball, she competed to national level.[9] She was selected by the Silver Ferns as a non-travelling reserve player.[10][11] Her first professional job was for Parekura Horomia, then a manager in the Department of Labour, who made her wait eight hours before he saw her, but then hired her immediately.[12] She later worked for the Māori Women's Welfare League before returning to the Department of Labour as deputy secretary. She worked as an adviser in Horomia's office when he was Minister of Māori Affairs.[13] From 2009 until her election to Parliament, she was chief executive officer of Ngāti Kahungunu iwi.[14]
Most political analysts predicted that Labour would hold Ikaroa-Rāwhiti, which Horomia had held since its formation for the 1999 election. At his last election in 2011, Horomia had won a majority of 6,541 votes.[24] Whaitiri won the by-election with a majority of 1659 votes over Mana Party candidate Te Hamua Nikora. Māori Party candidate Na Raihania, who had also been endorsed by National, came third.[25][26][27] Right-wing political blogger David Farrar called the by-election a "good victory for Labour", and commented that Whaitiri "could be one of the better Labour MPs".[28]
Whaitiri retained Ikaroa-Rawhiti during the 2014 New Zealand general election by a margin of 4,673 votes.[29] As an opposition MP for her first two terms, she was Labour Party spokesperson on water (2014–2015) and local government (2015–2017), and a member of the Māori affairs, primary production, and local government and environment select committees.[30]
On 30 August 2018, a staff member in Whaitiri's ministerial office alleged she was assaulted by the minister. Whaitiri was removed from her ministerial positions during an investigation and was not restored to them after the investigation found it "probable" that she had bruised the staffer.[35][36][37][38] During the interregnum she chaired the Justice select committee.[30]
On 4 September 2020 the Governor-General granted Whaitiri retention of the title "The Honourable" in "recognition of her term as a member of the Executive Council".[39]
On 3 May 2023, Whaitiri announced that she had officially notified the Speaker of the House that she had resigned from the Labour Party and was joining Te Pāti Māori (the Māori Party). She replaced Heather Te-Au Skipworth as Te Pāti Māori's candidate for her electorate at the 2023 New Zealand general election.[1] During her resignation speech, she attributed her decision to defect to her commitment to Māori political activism.[45] Whaitiri's defection was welcomed by Te Pāti Māori co-leader Debbie Ngarewa-Packer and President John Tamihere. Prime Minister Chris Hipkins learned about Whaitiri's defection after landing in London to attend the coronation of King Charles III.[46][45]
Following her defection, Acting Prime Minister Carmel Sepuloni confirmed that Hipkins had stripped Whaitiri of her ministerial responsibilities on 3 May. Kieran McAnulty became Hawke's Bay cyclone recovery lead minister, Hawke's Bay, Ayesha Verrall temporarily assumed the food safety portfolio, Peeni Henare took over the veterans portfolio, and Damien O'Connor temporarily took over the customs portfolio.[45] Permanent appointments were named on 10 May with Rachel Brooking becoming Minister of Food Safety and Jo Luxton becoming a new minister outside of Cabinet with responsibility for Customs.[47] Some commentary around Whaitiri's defection, including from Māori development minister Willie Jackson, focused on her apparent disappointment in not receiving a promotion into Cabinet in Hipkins' earlier reshuffles.[48][49]
Also on 3 May, Speaker of the HouseAdrian Rurawhe confirmed that Whaitiri would serve until the election as an independent member of Parliament under standing order 35.5, which avoids the waka-jumping provisions of the Electoral (Integrity) Amendment Act 2018 from being invoked. Rurawhe's decision not to invoke the waka-jumping law was criticised by National Party MPs Michael Woodhouse, Chris Bishop, and ACT Party leader David Seymour.[50] On 4 May, Rurawhe distinguished the Electoral Act from parliament's standing orders, stating that he had not received from Whaitiri a letter of resignation from Labour, despite her public statements, with the result that Whaitiri remained a Labour MP under electoral legislation, but was an independent MP for parliamentary purposes under standing orders.[51][52]
On 10 May 2023, Te Pāti Māori leaders Ngarewa-Packer and Waititi staged a haka to welcome Whaitiri to their political party. Speaker Adrian Rurawhe ordered Ngarewa-Packer and Waititi to leave Parliament since they had not received his permission or that of other parliamentary parties to hold the haka. Whaitiri stated that she was "joining a party that doesn't censor the voice of wāhine Māori (Māori women) ... I am joining a party that enables the voice of wāhine Māori to be heard, for our people to celebrate being Māori, unashamedly Māori".[53][54]
