Q:Information:  - William Lyon Mackenzie King (December 17, 1874  July 22, 1950) was the dominant Canadian political leader from the 1920s through the 1940s. He served as the tenth Prime Minister of Canada from 1921 to 1926, 1926 to 1930, and 1935 to 1948. He is best known for his leadership of Canada throughout the Second World War (19391945) when he mobilized Canadian money, supplies and volunteers to support Britain while boosting the economy and maintaining home front morale. A Liberal with 21 years and 154 days in office, he was the longest-serving prime minister in Canadian history. Trained in law and social work, he was keenly interested in the human condition (as a boy, his motto was "Help those that cannot help themselves"), and played a major role in laying the foundations of the Canadian welfare state.  - The Canadian federal election of 1940 was the 19th general election in Canadian history . It was held March 26 , 1940 , to elect members of the Canadian House of Commons of the 19th Parliament of Canada . Prime Minister William Lyon Mackenzie King 's Liberal Party was re-elected to their second consecutive majority government . The election was overshadowed by the Second World War , which caused many Canadians to rally around the government . In response to this , the Conservative Party of Robert Manion ran on a platform advocating the creation of an all - party national unity government and ran under the name `` National Government '' in this election . Though Manion was personally opposed to conscription , the Liberals faced intense pressure in Quebec on the question and promised not to institute the measure . This promise was to haunt the Liberals as they faced increasing pressure from the military and especially from English Canada to bring in the measure . To release him from his 1940 promise , King called a plebiscite in 1942 on the question . See also Conscription Crisis of 1944 . It was the most successful election for the Liberal Party in its history , in which it captured 73 % of seats in the House of Commons . Social Credit ran jointly with the New Democracy movement of William Duncan Herridge . Some candidates of the Conservative and Social Credit parties insisted on running under the traditional names , however . The Co-operative Commonwealth Federation ( CCF ) gained its first seat east of Manitoba , with the election of Clarence Gillis from Cape Breton Island . This election was the last one for its ailing leader , J.S. Woodsworth . Voter turn - out : 69.9 %  - William Lyon Mackenzie (March 12, 1795  August 28, 1861) was a Scottish-Canadian-American journalist and politician. He was the first mayor of Toronto and was a leader during the 1837 Upper Canada Rebellion.    What entity does 'canadian federal election' has the relation 'office contested' with?
A:
prime minister of canada