McKell was first elected to the New South Wales Legislative Assembly in 1917 and served continuously until 1947, when he resigned to become the 12th Governor-General of Australia.

[1][2] McKell led Labor to victory at the 1941 state election, defeating the United Australia Party / Country Party coalition of Alexander Mair and Michael Bruxner.

McKell and his government were re-elected for a subsequent term at the 1944 state election.

[3] This ministry covers the period from 8 June 1944 until 6 February 1947[4][5] when McKell resigned to become Governor-General of Australia.

There was a minor reshuffle in May 1946 following the appointment of Jack Tully as Agent-General for New South Wales in London.