Leader of the Official Opposition (Canada) in the context of "Jean Chrétien"

Lester Bowles Pearson (23 April 1897 – 27 December 1972) was a Canadian politician, diplomat, and scholar who served as the 14th prime minister of Canada from 1963 to 1968. He also served as leader of the Liberal Party from 1958 to 1968 and as leader of the Official Opposition from 1958 to 1963.

Born in Newtonbrook, Ontario (now part of Toronto), Pearson pursued a career in the Department of External Affairs went on to serve as the Canadian ambassador to the United States from 1944 to 1946. He entered politics in 1948 as Secretary of State for External Affairs, serving in that position until 1957 in the governments of William Lyon Mackenzie King and Louis St. Laurent. Pearson was also the seventh president of the United Nations General Assembly from 1952 to 1953. He was a candidate to become secretary-general of the United Nations in 1953, but was vetoed by the Soviet Union. He later won the Nobel Peace Prize in 1957 for organizing the United Nations Emergency Force to resolve the Suez Crisis, for which he received worldwide attention. After the Liberal Party was defeated in the 1957 federal election, Pearson handily won the leadership of the party in 1958. He suffered two consecutive defeats by Progressive Conservative prime minister John Diefenbaker in 1958 and 1962. He successfully challenged Diefenbaker for a third time in the 1963 federal election, winning a minority government. Pearson's Liberals won another minority government in the 1965 federal election.

The Official Opposition (French: Opposition officielle) is the largest party of the parliamentary opposition, which is composed of members of Parliament (MPs) who are not in government. Typically, it is the second-largest party in the House of Commons.

The Official Opposition is viewed as the caucus tasked with keeping the government in check. It is also generally viewed as the alternative government or "government in waiting". The Official Opposition maintains a shadow cabinet, with the leader of the Official Opposition at its head, of members of Parliament (MPs) and senators who often have the same portfolio areas of interest as actual ministers. The spokesperson for each portfolio is known as an opposition critic. In the event the government loses the confidence of the House or the Official Opposition party wins a general election, the party is ready to become the government.

Stephen Joseph Harper (born April 30, 1959) is a Canadian politician who served as the 22nd prime minister of Canada from 2006 to 2015. He is to date the only prime minister to have come from the modern-day Conservative Party of Canada, being the party's co-founder and serving as its first leader from 2004 to 2015. Since 2018, he has also been the chairman of the International Democracy Union.

Harper studied economics, earning his bachelor's and master's degrees in 1985 and 1991, respectively, from the University of Calgary. He was one of the founders of the Reform Party of Canada and was first elected to Parliament in the 1993 federal election in the riding of Calgary West. He did not seek re-election in 1997, and instead joined and later led the National Citizens Coalition, a conservative lobbyist group. In 2002, he succeeded Stockwell Day as leader of the Canadian Alliance, the successor to the Reform Party, and returned to Parliament as leader of the Official Opposition. In 2003, Harper and Peter MacKay negotiated the merger of the Canadian Alliance with the Progressive Conservative Party of Canada to form the Conservative Party of Canada. Harper was elected as the party's first leader in 2004. In the 2004 federal election, the Conservative Party lost to the Liberal Party led by Paul Martin. Following the defeat of Martin's government in a motion of no confidence, Harper led the Conservatives to a minority government in the 2006 federal election.