Tensions are mounting four days ahead of Canada's legislative elections as Liberal Prime Minister Justin Trudeau calls on citizens to vote strategically to block a Conservative surge, in which he faces a potential defeat at the hands of rookie Tory leader Erin O'Toole. "Do we keep moving forward? Or to go backward with the Conservatives?" Trudeau asks at a press conference in Montreal, before adding that there is "great concern about the far right" in Canada. IMAGES AND SOUNDBITES