Canada heads to the polls in closest election in country's history

Source: TheGuardian

1. Liberal party leader Justin Trudeau has surged into the lead in recent weeks
2. Trudeau hoping to oust incumbent prime minister Stephen Harper
3. Canada election 2015: a guide to the parties, polls and electoral system

Conservative leader, prime Minister Stephen Harper casts his ballot in Calgary, Alberta on Monday. Photograph: Jonathan Hayward/AP

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