Born in Liverpool, England to Scottish parents and raised in Glasgow, Scotland, Connell worked for a shipping company before coming to Canada at the age of 17 After seven years working in various jobs he moved to Calgary to train to become a Church of England minister. He was ordained a priest in 1896 and moved to Victoria, British Columbia in 1901 after several years of mission work in Alberta. He served as a vicar in various parishes (including two years in California) before retiring from the pulpit in 1923.
Connell was also involved with education occasionally teaching art at a private boys' school and botany at Victoria High School. He also wrote a weekly column on nature and geology for the Victoria Daily Times and later the Victoria Daily Colonist.
In 1932, Connell joined the League for Social Reconstruction and also joined the BC Reconstructionist Party formed by some supporters of the LSR in British Columbia. The short-lived party quickly joined the Co-operative Commonwealth Federation after it was formed in August of the same year.
Connell agreed to run for the provincial legislature as a CCF candidate in the 1933 provincial election, the new party won seven seats, including Connell's Victoria City riding. With the collapse of the governing Conservative Party, which was in such disarray it decided not to run any candidates, and the election of a Liberal government the CCF found itself as the official opposition in the British Columbia legislature. The party caucus met and named Connell as Leader of the Opposition.
Connell was a fervent believer of the social gospel movement. He was a moderate when compared to many more radical members of the party, including a majority of the party executive and much of the caucus, many who came to the CCF from the Socialist Party of Canada. The SPC which had co-founded the CCF in BC and remained in existence as a distinct entity. Connell urged co-operation with the Liberals and Conservatives on certain issues and was criticized by CCFers such as T. Guy Sheppard for refusing to call for a general strike against the Liberal government of "Duff" Pattullo. He also was the target of criticism for his opposition to class-based politics in the pages of the SPC's newspaper, The BC Clarion.
Tensions between Connell and the left-wing of the party emerged publicly when he stood up in the legislature to denounce the radical language of fellow CCF MP Ernest Winch who had given a speech on the merits of communism. At the 1936 party convention, Connell survived a vote of non-confidence in his leadership by a margin of 138-76. Connell's leadership again came under fire when he publicly opposed a resolution in favour of socializing banking and credit several weeks after it was approved. In July 1936, he issued a statement to the party executive and to the media revoking his support for the party platform approved by the convention three weeks earlier. The policy disagreement, which came to be known as the "Connell Affair" brought to a head a conflict in the party between moderates such as Connell and "revolutionary" Marxists such as Winch. Connell was expelled from the party in August and he promptly formed a new political party, the "Social Constructives" with three fellow MLAs from the CCF's 7 person caucus - Jack Price, R.B. Swailes and Ernest Bakewell. Also joining Connell was Victor Midgely, former leader of the One Big Union, and Bill Pritchard, editor and owner of The Commonwealth. Pritchard's defection left the BC CCF without a party newspaper.
With four MLAs in Connell's new "Social Constructive" caucus versus three remaining in the CCF, Connell was able to retain his position as Leader of the Official Opposition for the remainder of the life of the legislature.