In March 1981 Courtney announced that he had let his membership of the Labour Party lapse. Soon after, he withdrew from the Labour Party caucus and sat in the New Zealand House of Representatives as an independent. The Labour Party suffered defeats in the 1975, 1978 and 1981 general elections under the leadership of Bill Rowling. Courtney saw the momentum that had been gained under the Prime Ministership of the charismatic Labour leaderNorman Kirk was being eroded and lost by Rowling. Courtney firmly believed that change was needed in the leadership in order to beat Robert Muldoon and the National Party. Rowling was not an effective counter to Muldoon: in Parliament Muldoon had the measure of Rowling and Rowling was perceived as weak in the media. After Courtney's strong performance in the Nelson by-election in 1976 the 1978 Labour Party general election result was a "major disappointment" for Courtney. In the December 1980 leadership vote of confidence Courtney voted against Rowling. Rowling clung onto the Labour leadership by one vote-his own. Courtney's announcement of his independent candidacy for the 1981 general election was made only a few days before the 35th anniversary of the death of Harry Atmore, MP for Nelson from 1911 to 1946. Atmore had been the last independent MP to be elected to the New Zealand Parliament.
1981 election
At the 1981 election supporters rallied around Courtney's Independent campaign and, although defeated, it was by the very narrow margin of 698 votes. Courtney took 37.0 per cent of the total vote, 3.4 percentage points behind the Labour candidate, and nearly three times as many votes as the National candidate's share of the vote. This was the best result by an independent candidate in New Zealand elections in nearly 40 years.
Local politics
Courtney was an elected member of Nelson City Council for six years during the 1970s under Mayor Roy McLennan; for some of that time, he was also a Member of Parliament. He had a three-year gap and then became a member of the city council for another three-year term under Mayor Peter Malone. Courtney came out of political retirement for the 2016 local elections. Of the 12 successful candidates, Courtney was elected with 6,743 votes. Courtney was re-elected with 8,601 votes in the 2019 local elections.
Outside politics
Courtney owned and operated supermarkets in Nelson and at its peak, he had five of them. He retired to Australia in about 2000. He returned to live in Nelson in late 2014 or early 2015.