 He was successful at the 1919 election, and won a seat in the Division of Denison for the Nationalist Party of Australia.McPhee was appointed to cabinet as Chief Secretary and Minister for Railways from 22 August 1922, but resigned both posts a year later for business reasons.In October 1923, the Premier Walter Lee was forced to resign by dissidents from the Nationalist and Country parties, and Joseph Lyons was asked to form a Labor government by the Governor of Tasmania.