He was a member of the Australian Labor Party (ALP) and held ministerial office in the Whitlam government as Minister for External Territories (1972–1973), Science (1972–1975), and Defence (1975).

Morrison was born in Lithgow, New South Wales and graduated with an honours degree in economics from the University of Sydney in 1949.

He was a diplomat in the Department of External Affairs from 1950 to 1969, with postings to London, Moscow, Washington, D.C., Bangkok and Kuala Lumpur.

[4] In 1969 Morrison resigned from the diplomatic service to successfully contest the seat of St George in the 1969 election for the Australian Labor Party.

He also became a member of the Select Committee on Aircraft Noise, a matter of relevance to his electorate, which was close to Sydney Airport.