[3] Courtney was the vice-chairman of the Sydenham Labour Representation Committee and organised campaigns in the electorate for Mabel Howard and later Norman Kirk in the 1960s.
[7] When Nelson's MP Sir Stan Whitehead died in early January 1976, Courtney stood for the Labour nomination in the subsequent by-election.
To prevent a split in the membership Arthur Baysting, the secretary of the Nelson Labour Electorate Committee (LEC), pushed for Courtney to be selected believing him to be the most electable alternative to Palmer.
Among those that were unsuccessful in their bid for the Labour Party nomination were Sonja Davies, Frank O'Flynn and the aforementioned Geoffrey Palmer.
He stressed Nelson's needs as a community as the major theme of his campaign, which was managed by MPs Colin Moyle and Arthur Faulkner.
In July 1976 Courtney presented a petition to Parliament, signed by over 20,000 people (including the Nelson based writer Maurice Gee), asking the Government to reconsider its decision to allow nuclear warships into New Zealand ports (the USS Truxtun and USS Long Beach were expected later in the year).
In September 1976 Courtney followed up and put a parliamentary question to the Prime Minister, Robert Muldoon, to ascertain the cost of the USS Truxtun visit alone to the New Zealand taxpayer and it was estimated to be at least $110,000.
[15] New Zealand only began to reduce lead in petrol in 1986 and did not remove it completely until 1996, twenty years after Courtney raised the issue.
Courtney saw the momentum that had been gained under the prime ministership of the charismatic Labour leader Norman Kirk (1972–74) 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.
In December 1978, Courtney after visiting the Ross Sea region stated that "New Zealand is getting tremendous value for its modest investment in Antarctic research."
New Zealand's marine environment, the climate and weather systems and patterns are intrinsically connected to Antarctica and the Southern Ocean.
Courtney saw the key priorities for New Zealand as multidisciplinary scientific research, environmental assessment and protection, and fisheries monitoring and surveillance.
In August 1979 he openly contradicted Rowling (who held the neighbouring Tasman electorate) by stating his support for a private jet-foil service across the Cook Strait.
[25] Courtney "championed the cause of small businesses" within the Labour caucus and described them as the "lost tribe" of New Zealand's commercial world (Courtney has the distinction of being the last member of any Labour caucus with a retail business background after the retirement of Paddy Blanchfield MP for the West Coast at the 1978 election).
[28] In September 1979, Marilyn Waring, the National MP for Waipa, noted: "what Mel Courtney is doing at the moment is very significant.
"[29] And, the Labour Party caucus "unanimously passed a resolution expressing confidence in Mr Courtney as a colleague.
As the opposition convener of the fisheries sub-committee on production and marketing, he asserted "the policy is falling apart" expressing the view of many commercial fishers: "The industry expanded so rapidly it was overcapitalized with too many boats...the inshore fleet expanded and joint venture and duty free boats exerted further pressure" Commercial Fishing Magazine, June 1980 pg.5.
There was media speculation that Courtney might defect from Labour and join National or Social Credit instead due to increasing differences over direction.
[3] In March 1981 Courtney withdrew from the Labour Party caucus and sat in the New Zealand House of Representatives as an independent.
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.
[38] In September 1981 Courtney introduced a private members' bill into parliament that enabled the Nelson based Cawthron Institute to widen its scope.
It was an important milestone in the organisation's history paving the way for the trust "to enter joint ventures or develop its own manufacturing capability".
[40] In October 1981 Courtney supported a motion in parliament that would allow a Social Credit MP to become a representative on the Electoral Boundaries Commission alongside the two major parties, Labour and National.