Also in that year he married Marjorie Darcy and was sent home from his army chaplaincy in New Guinea after questioning the differences in treatment between officers and troops and his Christian burial of a Japanese pilot.
The couple settled in Woollahra, where the Dowding manse became a central meeting place for the Australian Labor Party's left faction, including Les Haylen, Eddie Ward and H. V. Evatt.
Dowding was also involved in the Petrov Affair, becoming the confidant and spiritual advisor of Alan Dalziel, one of Evatt's staffers who was accused of being a Soviet spy.
He was a campaigner for a wide variety of causes, serving as president of the Western Australian Council for Civil Liberties, convener of People for Nuclear Disarmament, president of the Western Australian branch of Amnesty International, founder of Freedom from Hunger in WA, chairman of the Refugee Task Force and West Australians for Racial Equality, and national vice-president of the United Nations Association of Australia.
He and his second wife divorced and he remarried Jane Hutchison, an Anglo-Indian nurse he met in Nigeria working with the Save the Children Fund, in the 1960s.