Canadians will face an unusually polarized political landscape for at least the next four years after one of the most stunning election outcomes in their country’s 144-year-old history.

The new Parliament will be dominated by the Conservatives, led by Prime Minister Stephen Harper, who in elections Monday turned their five-year-old minority government into a solid majority.

Expanding on their base in western Canada, the Tories captured a wide swath of seats in and around Toronto, according to preliminary results released early Tuesday. They made deep inroads into increasingly influential immigrant communities, especially those of Chinese and South Asians.

But the biggest shocks were on the opposition side. The Liberals, long considered Canada’s natural governing party for their unerring ability to straddle the political center, won only 34 of 308 parliamentary seats. Their leader, Michael Ignatieff, resigned Tuesday.

The official opposition will be the left-leaning New Democratic Party, which almost tripled its representation to 102 seats. The NDP not only took seats from the Liberals but also virtually wiped out the Bloc Quebecois, the voice of French-speaking Quebec separatists in Ottawa for two decades.

The Bloc plummeted from 47 seats to four. Its long-serving leader, Gilles Duceppe, announced his resignation as the results came in late Monday.

Quebecers are generally more liberal on social and economic issues than their English-speaking compatriots, making them receptive to the NDP’s interventionist platform. Even so, Antonia Maioni, director of the Institute for the Study of Canada at McGill University in Montreal, described the NDP’s gains in the province as a “complete protest vote” against all the other federalist and sovereigntist parties.

“This was a sweep in many senses — a sweep of seats and a sweep of cleaning house,” she said.

The separatist movement remains strongly represented at the provincial level by the Parti Quebecois, which has recently run ahead of the ruling Liberals in opinion polls. A provincial election will be held next year.

Canada’s business community welcomed the Tory win and the setback for the separatists. Michael Gregory, a senior economist at BMO Capital Markets, said, “A majority government does provide a little more flexibility for policies that have been attractive to investors.”

Harper said the new government’s top priority is to reintroduce a business-friendly budget that the opposition parties had threatened to defeat before the election. It includes the final stage of a five-year plan to cut the corporate tax rate from 21 percent to 15 percent.

Despite their electoral triumphs, the Tories and the NDP face considerable challenges. Harper, who has been a divisive figure since taking office five years ago, said, “We are intensely aware that we are and must be the government of all Canadians, including those that did not vote for us.”

Jack Layton, the NDP leader, will preside over what Maioni described as “a motley crew” of a caucus. The NDP previously held only one seat in Quebec. Many of its new MPs are political neophytes who had virtually no on-the-ground organization; one spent part of the campaign vacationing in Las Vegas.

The toughest decisions, however, confront the Liberals. Some members are likely to push for a merger with the NDP, while others argue that Canada still has room for a middle-of-the-road party.

Pointing to similar trends elsewhere, Maioni said the Liberals were “in the very difficult, tenuous position of a centrist party, especially a party that has made its brand as the movable center.”

In resigning as party leader, Ignatieff said he planned to return to teaching. But he insisted: “Canada really needs a party of the center. The surest guarantee . . . is four years of Conservative government and four years of NDP opposition.”

— Financial Times