By IAN AUSTEN OTTAWA — The Conservative Party will again govern Canada, this time with a majority, following the country’s fourth election in seven years.
In addition, incomplete results late Monday night clearly indicated that the New Democratic Party, a movement with socialist roots, will form the official opposition, which would mean that the vote is likely to significantly reshape Canada’s political left.
It was the first time since Canada became a nation in 1867 that the Liberals, the most successful political party in the country’s history, finished in third place.
The unexpected rise over the campaign’s final days of the New Democrats, a party historically distinguished by its lock on third place, was also devastating for the Bloc Québécois, a party that has championed Quebec separatism for the last 20 years. It was reduced to just two seats and its defeated candidates included Gilles Duceppe, its long time leader.
For Prime Minister Stephen Harper, obtaining a majority was the overriding focus of his campaign. In the end, he did much better than the dozen seats he needed to secure the 155 required for control, acquiring 165, the Canadian Broadcasting Corporation projected. The New Democratic Party won 105 seats, well above its previous record of 45, while the Liberals held only 35. Elizabeth May, the leader of the Green Party, became its first, and only, elected member.
The Liberal leader, Michael Ignatieff, who had appeared in danger of losing his seat, said he would remain in his post if that was the desire of his party.
“Democracy teaches hard lessons,” he told supporters in Toronto.
A flood of on-the-one-hand, on-the-other commentary in the final days of campaign portrayed the rise of the New Democrats as both a gift for the Conservatives (by splitting left-of-center votes with the Liberals) and a menace to the them (by stealing away seats). The early returns suggested that the result was more of the former.
Most of the New Democrats’ gains came in Quebec, giving the party its first significant presence there since its founding during the Great Depression. Late in the evening, it appeared that it had broken the electoral hold of the separatist Bloc Québécois, which after 20 years appeared to have lost its appeal.
Many of the new members of Parliament from the New Democrats in Quebec are little known and inexperienced and, in some cases, did not even campaign. Several of them are university students.
Although even his opponents acknowledged that he ran a strong campaign in his debut as Liberal Party leader, Mr. Ignatieff, a former journalist and director of a human rights center at Harvard University, had difficulty connecting with voters. For more than a year before the start of the campaign, the Conservatives broadcast relentless attack ads portraying him as a kind of carpetbagger who returned to Canada for personal aggrandizement after spending most of his life in Britain and the United States.
It appeared that the rise in support for the New Democrats split votes in Ontario, the most populous province, to the benefit of the Conservatives, who had lagged in that province under Mr. Harper. That appeared to allow Mr. Harper to gain his majority with just 40 percent of the popular vote.
Throughout the campaign, Mr. Harper limited his public exposure to a small number of tightly controlled events. Reporters traveling with him were restricted to a total of four questions a day, although they did not necessarily receive four corresponding answers. Sometimes when reporters asked contentious questions, partisan crowds were whipped up into cheers to drown them out.
“The key to understanding Stephen Harper is his determination to establish the Conservative Party as the dominant party in Canada,” said Michael Bliss, a historian. “He wants to gradually shift the shade of government from red to blue.” In Canada, the Conservatives are blue.
In his standard campaign speeches, Mr. Harper emphasized the economic dangers and instability he said would result if the Conservatives failed to win a majority. Any drastic new plans he would introduce if he gained such power were remarkably absent.
He warned that if he did not win a majority, the government could end up controlled by a coalition of the Liberals, New Democrats and the Bloc Québécois, an alliance he derided as “the socialists and the separatists.”
That left Mr. Ignatieff spending much of the early campaign denying any plans to take power other than by winning the largest number of seats.
While majority governments bring stability, they also give the prime minister exceptional power, and the Liberal campaign also emphasized what its members called Mr. Harper’s antidemocratic leanings.
His government fell after becoming the first to be found in contempt of Parliament for not turning over accurate cost figures for several government programs. Some leaders of quasi-independent government agencies found themselves jobless when they tried to contradict Mr. Harper’s government. And twice Mr. Harper took the unusual step of shutting down Parliament for what critics said was only to avoid political embarrassment.
This article has been revised to reflect the following correction:
Correction: May 3, 2011
Due to an editing error, an earlier version of this article referred incompletely to Michael Ignatieff's debut. It as Liberal Party leader, not as an elected politician.