Throughout most of the 20th century, national unity has been the primary aim of every Canadian government: leaders of both the English-speaking majority and the French-speaking minority have cooperated to develop a united Canada with a great destiny to which differences arising from national origin were subordinate. In the 1970s, this unity was challenged by a growing demand for French Canadian autonomy. Despite cultural division, national unity has remained a basic factor in Canadian foreign policy. Two elements have contributed to the growth of Canadian nationalism—deliberate government policy and reaction against overidentification with either the United Kingdom or the United States.
Continuity of policy characterizes party relationships. The Liberal Party (LP), which held office from 1935 to 1957 and again (except for part of 1979) from 1968 to 1984, is nationwide in its representation but has its main strength in Québec. It traditionally emphasizes trade and cultural relationships with the United States, while its principal rival, the Progressive Conservative Party (PC), which held power from 1957 to 1968, from May to December 1979, and again since the end of 1984, stresses Canada's relationships with the UK. In economic policy, the Liberals generally champion free trade, while the Conservatives favor a degree of protection; but practical political considerations have modified this distinction.
The Cooperative Commonwealth Federation (CCF) was a farmer-labor party with its main strength in Saskatchewan. Its foreign policy was much like that of the British Labour Party, but with an admixture of traditional Canadian prairie radicalism. It merged with the Canadian Labour Congress to form the New Democratic Party (NDP) in 1961. The Social Credit Party (SCP) has headed governments in Alberta and British Columbia but has not done well nationally. In June 1962, the group collapsed into independent factions, leaving only five representatives in the Commons. In September, the Québec wing of the party united to form the Ralliement des Créditistes, which after the 1965 elections became the new focal point of French Canadian interests.
After 22 years of uninterrupted rule, the Liberals were defeated by the PC in the 1957 elections. This was widely interpreted as a vote of protest against individual Liberal ministers and high taxes, as a reflection of concern over US economic penetration, and as a demonstration of widespread feeling that it was "time for a change." In the general election on 31 March 1958, the PC was returned to power with an unprecedented majority, taking 208 of the 265 seats. The LP was reduced to 49 seats, the smallest number in its history. In the election of June 1962, the PC lost 92 seats. The following February, the PC government lost a vote of confidence, the major issue being defense policy and the refusal of the prime minister to accept nuclear weapons from the United States. In the election of April 1963, the resurgent Liberals gained an additional 29 seats for a total of 129 (four short of a parliamentary majority). With some support from the SCP, Liberal leader Lester B. Pearson formed a new government.
In April 1968, the new Liberal Party leader, Pierre Elliott Trudeau, was elected prime minister in a colorful campaign emphasizing personality more than specific issues. In the June general election, which he called for almost immediately, the LP took 155 seats and the PC 72; the SCP lost all five of its seats. In the general elections of 30 October 1972, the Liberals lost their parliamentary majority, winning only 109 seats to the PC's 107. The NDP increased its representation from 22 seats to 31, and the Créditistes, who had resumed calling themselves the SCP in 1971, won 15 seats. When the NDP decided to support the continuance of Liberal rule, Prime Minister Trudeau formed a new cabinet. The Liberal-NDP alliance collapsed on 8 May 1974 when, for the first time in Canadian history, the government received a vote of no confidence on a budget bill. Elections were called, and the campaign was fought largely on the issue of inflation, with the PC calling for a system of wage and price controls. In the elections of 8 July 1974, the Liberals regained their majority.
In the general elections of 22 May 1979, the Liberals lost to the PC, taking 114 seats of the now 282-seat Parliament to the PC's 136, and were unable to form a government in any province. However, on 13 December 1979, the government of Prime Minister Joe Clark was defeated by a Liberal and NDP coalition on a vote of no confidence on a budget bill that called for an increase of 18 cents a gallon in the excise tax on gasoline. Trudeau, who in November had announced his planned retirement, decided to continue as Liberal leader, and again became prime minister after elections on 18 February 1980 gave the Liberals 147 seats. Four years later, on 29 February 1984, Trudeau again announced his impending retirement, and his party chose John Turner as successor. Brian Mulroney became prime minister following a landslide PC victory in the September 1984 elections, which gave the PC 211 seats, the Liberals 40 (their lowest number ever), the NDP 30, and an independent 1. However, the Liberals regained strength over the next year, and in 1985 won the Québec general election and, in a coalition with the NDP, ended 42 years of PC government in Ontario.
In 1993, the PC fell from power, primarily due to one of the worst Canadian recessions in nearly 60 years and the failure of the PC government to implement constitutional reforms. Brian Mulroney resigned and was succeeded by Kim Campbell. Liberals soundly defeated the PC in the October 1993 election, with 177 of the 295 seats (up from only 80 in 1988). The PC retained only two of their 157 seats. The Liberal party named Jean Chrétien as the new prime minister.
The Liberal Party's majority in Parliament was reduced to 155 in elections called by Chrétien in June 1997. The majority of opposition seats were won by the right-wing populist Reform Party, formed in Alberta in 1988 and led by Robert Manning, which increased its representation to 60 seats, winning broad support in the western provinces. Other party totals were Bloc Québécois, 44; New Democratic, 21; Progressive Conservative, 20; and Independent, 1. In January 2000, members of the Reform Party voted to create a broader conservative grouping called the Canadian Alliance, uniting the western-based, populist Reform Party with the eastern-based Progressive Conservatives in an attempt to eventually unseat the dominant Liberals.