After graduation he worked with the Extension branch of the Ontario Ministry of Food and Agriculture designing farm buildings, drainage systems and conservation measures.
Milne first ran for the Liberal Party of Canada in the 1972 federal election in the riding of Peel—Dufferin—Simcoe, west of Toronto.
He was defeated by Progressive Conservative Ellwood Madill but prevailed in a rematch two years later in the 1974 federal election.
[2][3] As a result of redistribution, Milne ran for re-election in the new riding of Brampton—Georgetown in 1979, losing to John McDermid of the Tories.
In 2013 he drove his Model A from Vancouver down to San Francisco, then across the US from the Golden Gate Bridge to Times Square in New York City, before driving it back home to Canada, 6,742 miles in total.