Who are the candidates?

Canada has 21 registered political parties, but most are fringe and only six have party leaders running as candidates in this election cycle.

• Justin Trudeau, Liberal Party of Canada:
  The 47-year-old incumbent candidate is considered a beacon of progressive values in an international climate of growing right-wing sentiment. But his golden boy status took a heavy hit in recent months when photos of the prime minister wearing blackface emerged. He is also battling accusations that he intervened in the prosecution of a Quebec engineering firm on corruption charges. Former US President Barack Obama made the unprecedented move of endorsing Trudeau last week, perhaps sensing that the candidate needed support.
• Andrew Scheer, Conservative Party of Canada:
  Trudeau's main challenger for the premiership, 40-year-old Scheer is a career politician running on a platform of balancing the federal budget and eliminating a new national tax on fossil fuels. He has largely marketed himself as a Trudeau alternative. 
• Jagmeet Singh, New Democratic Party:
  Singh, 40, is the first non-white leader of a federal party in Canada and an open follower of Sikhism. With Singh's charisma and a star quality to challenge Trudeau's, this minority party has been able to win support away from the Liberals in recent weeks.
• Elizabeth May, Green Party of Canada:
  May, 65, is the longstanding leader of Canada's Greens. Growing support for environmental initiatives has allowed the Greens to steal votes away from the two majority parties.
• Yves-Francois Blanchet, Bloc Quebecois:
  Blanchet, 54, leads the French-speaking province's nationalist party. Despite dwindling interest after two failed referendums, Blanchet's leadership has reignited the independence movement in Quebec. He drew ire from Trudeau and Scheer on Sunday when he suggested the possibility of another attempt.
• Maxime Bernier, Peoples Party of Canada:
  "Mad Max" Bernier, 56, leads the anti-immigration, anti-corporate welfare, anti-budget deficit party that, while holding only minor support, could draw votes away from Scheer's conservatives.
   

What are the issues?

This election cycle has had an atypically strong focus on candidates over policy. While health care and the environment are among the important topics, the vote is largely seen as a referendum on Trudeau, whose first term has included a national carbon tax, the legalization of marijuana, and the approval of the Trans Mountain pipeline project. He also brokered a new trade deal with Mexico and the US and oversaw a strong economy. 

Scheer, meanwhile, has been criticized for holding dual US-Canadian citizenship as well for embellishing aspects of his resume.

The minority parties have made a lot of headway in recent weeks, which is likely to translate into underwhelming support for the two main parties and no majority winner.

How does the election process work?

Canada has a first-past-the-post system for its 338 "ridings," or voter districts. The candidate with the most votes wins the parliamentary seat for that riding.

A party can form a majority government if it wins 170 seats or more, even if it receives less than half the votes.

If a party wins the most seats, but the total is less than 170, it can form a minority government with a smaller party. 

If neither of the two main parties wins more than 170 seats, Trudeau as the incumbent prime minister has the first shot at forming a minority government, even if the conservatives win more seats overall.

What is the likely outcome?

Conservatives and Liberals have been effectively tied for weeks, with polls showing both parties winning around 33% of the vote.

Pollsters don't expect either to win a majority government. Conservatives would be likely to ally with the Bloc Quebecois in a minority government scenario while the New Democratic Party could be a minority partner for the Liberals.

It's been 84 years since a first-term prime minister with a parliamentary majority, as Trudeau currently has, did not win reelection.

When are the results in?

Final polls will close in British Columbia at 7 p.m. (2 a.m. UTC).  Preliminary results are expected Monday evening in Canada.

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