He later served as the inaugural Chief Judge of the Land and Environment Court of New South Wales from 1980 to 1985, as well as presiding over the 1984 McClelland Royal Commission into British nuclear tests in Australia.

[2] McClelland won a scholarship to attend the University of Melbourne in 1932, but dropped out in 1934 and joined Victorian Railways as a clerk.

Identifying as a Trotskyist, he joined the Communist-dominated Federated Ironworkers' Association (FIA) and came under the influence of union leader Laurie Short and Marxist scholar Guido Baracchi.

He later worked for ARC Engineering Company and was a shop steward, but in 1942 was expelled from the FIA for engaging in disruptive activities and terminated from his employment for "anti-war deviationism".

[1] He also represented Short from 1950 to 1952 in his successful attempts to remove the leadership of the FIA, briefing barrister and future governor-general John Kerr.

By the mid-1950s he had abandoned Trotskyism and was approached to join the anti-communist Democratic Labor Party, ultimately letting his ALP membership lapse.

In 1980 McClelland was appointed the first chief judge of the Land and Environment Court of NSW, holding that office until his 70th birthday in June 1985.

In 1984, as Justice McClelland, he was President of the Royal Commission into British nuclear tests in Australia at Maralinga.

He was reviled by the right as is indicated in Roddy Meagher's portrait in Quadrant, and associated with Edmund Campion, Patrick White, Manning Clark and Donald Horne.