He was a prominent campaigner in the 1933 secession referendum and served on the delegation to the British parliament which ultimately failed to achieve the movement's aims.

[3][4] In 1919, Watson passed an examination to join the Commonwealth Public Service as a clerk in the Postmaster-General's Department, later transferring to the Federal Taxation Office.

[5] In 1930, a two-year legal battle against the federal government over a tax debt ended when his final appeal was rejected by the High Court of Australia in Watson v Commissioner of Taxation.

[1] Watson was an unsuccessful candidate for the House of Representatives on three occasions, standing in the seat of Fremantle at the 1928, 1929 and 1931 federal elections.

Watson joined the delegation with Sir Hal Colebatch, Matthew Moss and James MacCallum Smith (MLA and proprietor of The Sunday Times newspaper).

They returned to Perth in 1935 frustrated at the British Parliament's refusal to accept the petition and by 1938 the Dominion League had become inactive.