NDP leader Jagmeet Singh and the Bloc's Yves-Francois Blanchet have won praise for campaigns in which they cast themselves as alternatives to the leaders of the big parties.
Canadians vote Monday to determine whether centrist Prime Minister Justin Trudeau, who swept into office four years ago as a charismatic figure promising "sunny ways," will remain in power after two major scandals.
He was shaken during the campaign by a blackface scandal and has been dogged by criticism of his handling of a corruption case involving a major Canadian construction company. Trudeau, the son of former Canadian Prime Minister Pierre Trudeau, has also had to overcome a sense of fatigue with his government.
Left-wing activists have also accused Trudeau and his government of breaking their promises to the Indigenous communities in Canada who have seen their lands being invaded by oil companies and pipelines.
"When the prime minister says that this pipeline expansion will be done no matter what, and his minister adds that Canada will not be able to accommodate all Indigenous concerns, what that means is that they have decided to willfully violate their constitutional duties and obligations," Romero Saganash, First Nations lawmaker from the Quebecois New Democratic Party, said last year in a parliamentary session speaking of Trans Mountain pipeline expansion.
"Sounds like a most important relationship, doesn't it? Why doesn't the prime minister just say the truth and tell Indigenous peoples that he doesn't give a fuck about their rights?"
The liberal prime minister has also adopted an aggressive foreign policy against the government of Venezuela, joining the so-called "Lima Group", made up of right-wing governments in Latin America, and backed by the government of Donald Trump. The group's main objective is to overthrow the leftist government of Nicolas Maduro using economic and diplomatic pressure.
Trudeau's Liberals and the main opposition Conservatives led by Andrew Scheer are in a neck-and-neck race, according to opinion polls.
"The truth is it's a coin toss right now," said Ipsos pollster Darrell Bricker.
A year ago, no one would have predicted that Trudeau risked being the first prime minister since the 1930s to secure a parliamentary majority and then fail to win a second term.
The latest opinion polls suggest he may narrowly avert that result and could return to office with a minority in the 338-seat House of Commons. That would still leave Trudeau in a weakened position and needing the support of left-leaning opposition parties Five parties are contesting Canada’s federal election to push through key pieces of legislation.
Trudeau's main rival has proven to be a determined opponent. One of the defining moments of the campaign was when Scheer attacked Trudeau during the English-language debate.
"He can't even remember how many times he put blackface on, because the fact of the matter is he's always wearing a mask," Scheer said. "Mr. Trudeau, you are a phony and you are a fraud and you do not deserve to govern this country."
The liberal image of Trudeau took a severe blow when pictures emerged early in the campaign of him wearing blackface in the early 1990s and in 2001.
Trudeau had already been wrestling with the fallout from accusations he pressured his justice minister to help shield engineering firm SNC-Lavalin Lavalin Group Inc from corruption charges. In August, a top watchdog said Trudeau breached ethics rules.
Given the fact that neither of the front-runners could come away with a parliamentary majority, it is the smaller left-leaning New Democratic Party (NDP) or the separatist Bloc Quebecois that could end up holding the balance of power.
Only six weeks ago, both those parties looked like they were heading toward electoral disaster. But NDP leader Jagmeet Singh and the Bloc's Yves-Francois Blanchet have won praise for campaigns in which they cast themselves as alternatives to the leaders of the big parties.
Singh has deployed a social media-driven strategy in order to attract young voters, who have historically been less inclined to vote. Polls suggest that his push might be working as his party might play an important role in the next government as Trudeau would look to form a coalition.
He also made it clear that his fight against the Trans Mountain would continue even if he is part of a coalition government.
“This is something that I’ve been really clear on. I am fully opposed to the Trans Mountain, I have been opposed to it, I will continue to be opposed to it,” Singh told reporters days before the elections. “We’ve been fighting the pipeline before, we’re going to continue to fight it, we’re always going to fight it.”
Polls open in the Atlantic province of Newfoundland at 8:30 a.m. local time and voting ends in the Pacific Coast province of British Columbia at 7 p.m. local time.
EKOS Research pollster Frank Graves said Liberals needed turnout to be similar to four years ago or otherwise the Conservatives may have an edge.
"We may well be waiting until the final vote tallies in British Columbia to see who will win on Monday," Graves said.