Bob Jones, leader of the New Zealand Party also contested the seat, creating a three-way competition that enabled a Labour victory.
In his maiden statement, delivered on 23 August 1984, Dunne spoke about the economic policy of the previous government which had led to high unemployment that was felt particularly by young people.
He won his seat again in the 1990 election, but the Labour Party suffered defeat, and Dunne thus lost his ministerial posts.
With the departure of leading right-wingers like Roger Douglas, Richard Prebble and David Caygill he found himself isolated.
Together, the defectors and Dunne established the United New Zealand party, with a total of seven MPs, led by Clive Matthewson.
[14] United eventually established a coalition with the National Party, with the deal seeing Dunne return to Cabinet as Minister of Internal Affairs and Revenue.
Dunne, by virtue of his personal support, won the newly formed seat of Ohariu-Belmont, but all other United MPs suffered defeat.
Mostly as a result of a strong performance by Dunne in a televised political debate, United Future surged unexpectedly in support, winning 6.69% of the nationwide party vote.
Don Brash expressed a lack of amusement with Dunne's decision to support a Labour-led coalition government.
Brash expressed astonishment at Dunne accepting the ministerial portfolio of Revenue while remaining outside Cabinet.
[17] After the 2005 New Zealand general election, United Future retained only two list Members of Parliament, Judy Turner and Gordon Copeland.
[19] Between December 2008 and August 2009, Dunne served as the chairman of the Emissions Trading Scheme Review Committee.
[20] In 2010, as Minister of Revenue, Dunne introduced the Taxation (Income-sharing Tax Credit) Bill to Parliament in September 2010, to give effect to United Future's policy of allowing couples raising dependent children up to the age of 18 years to share their incomes for tax purposes.
In April 2011, the government announced the establishment of a statutory Game Animal Council, another United Future initiative agreed to as part of the 2008 confidence and supply agreement.
He also oversaw the He Tohu project which saw three of New Zealand's most precious constitutional documents – the 1835 Declaration of Independence, the 1840 Treaty of Waitangi, and the 1893 Women's Suffrage petition – rehoused in a purpose-built facility at the National Library.
[24] In mid-2013 Dunne refused to hand over all 86 emails between himself and Fairfax journalist Andrea Vance relating to the inquiry into the leaking of Rebecca Kitteridge's GCSB report following its illegal spying on Kim Dotcom.
Prime Minister John Key told Dunne that if he would not co-operate with the inquiry he would have to resign his ministerial positions – which he did on 7 June.
[25] However, in December 2013 Parliament's powerful Privileges Committee found that Dunne was entirely within his rights to decline the Henry Inquiry access to his emails.
In a 2008 interview, Dunne suggested it may be time to review New Zealand's abortion laws and leave the decision to a woman and her doctor, based on informed consent.
[31] From 2007, Dunne rebranded United Future as a centrist party, based on promoting strong families and vibrant communities.
[citation needed] Dunne has summarised his political views in two books, Home is Where My Heart Is (2002) and In the Centre of Things (2005).