TORONTO - Conservative Prime Minister Stephen Harper won his coveted majority government in elections Monday that also marked a shattering defeat for the opposition Liberals, preliminary results showed.

Harper, who took office in 2006, has won two elections but until now had never held a majority of Parliament's 308 seats, forcing him to rely on the opposition to pass legislation.

While Harper's hold on the 308-member Parliament has been tenuous during his five-year tenure, he has managed to nudge an instinctively center-left country to the right. He has gradually lowered sales and corporate taxes, avoided climate change legislation, promoted Arctic sovereignty, upped military spending and extended Canada's military mission in Afghanistan.

Elections Canada reported preliminary results on its website, giving the Conservatives 164 seats, which will give Harper four years of uninterrupted government.

"It's stunning. We're elated," Conservative lawmaker Jason Kenney said in an interview with CBC. "We'll be a government for all Canadians."

The leftist New Democratic Party was projected to become the main opposition party for the first time in Canadian history with 106 seats, in a stunning setback for the Liberals who have always been either in power or leading the opposition.

Former colleagues of Harper say his long-term goals are to shatter the image of the Liberals _ the party of former Prime Ministers Jean Chretien, Lester Pearson and Pierre Trudeau _ as the natural party of government in Canada, and to redefine what it means to be Canadian.

Harper, who comes from the conservative western province of Alberta, took a major step toward that goal on Monday night as the Liberals dropped to 35 seats from 77, according to the preliminary results.

Liberal leader Michael Ignatieff congratulated Harper and New Democrat leader Jack Layton and accepted responsibility for the "historic defeat."

"I will play any part that the party wishes me to play as we go forward to rebuild," said Ignatieff, who even lost his own seat in a Toronto suburb.

Stephen Clarkson, a professor of political science at the University of Toronto, said Harper will now be considered a transformative figure in Canadian history.

"It's a sea change," Clarkson said.

The New Democrats' gains are being attributed to Layton's strong performance in the debates, a folksy, upbeat message, and a desire by the French-speakers in Quebec, the second most populous province, for a new face and a federalist option. Voters indicated they had grown weary with the separatist Bloc Quebecois, which had a shocking drop to three seats from 47 in the last Parliament.

The NDP's gains marked a remarkable shift in a campaign that started out weeks ago looking like a straight battle between Harper and Ignatieff, with the 60-year-old Layton recovering from prostate cancer and a broken hip.

Harper campaigned on a message that the New Democrats stood for higher taxes, higher spending, higher prices and protectionism. He called the election a choice between "a Conservative majority" and "a ramshackle coalition led by the NDP that will not last but will do a lot of destruction."

Gerry Nicholls, who worked under Harper at a conservative think tank, has said that having the New Democrats' as the main opposition party would be ideal for Harper because it would define Canadian politics in clearer terms of left vs. right.

The Conservatives have built support in rural areas and with the "Tim Horton's crowd" _ a reference to a chain of doughnut shops popular with working class Canadians. They also have blitzed the country with TV attack ads, running them even during telecasts of the Academy Awards and the Super Bowl.

Lawrence Martin, a political columnist for The Globe and Mail newspaper and author of "Harperland: The Politics of Control," calls Harper "the most autocratic and partisan prime minister Canada has ever had."

But to remain in office through the longest period of minority government in Canadian history, Harper has had to engage in a constant balancing act. He has deliberately avoided sweeping policy changes that could derail his government, but now has an opportunity to pass any legislation he wants with his new majority.