OTTAWA/WINDSOR, Ontario, Sept 17 (Reuters) - Canadian Prime Minister Justin Trudeau on Friday acknowledged the unpopularity of his pandemic election and intensified his calls on progressive voters to back his campaign, with his bid for re-election at risk of being doomed by low turnout. Opinion polls show Trudeau"s Liberals neck and neck with the opposition Conservatives led by Erin O"Toole ahead of Monday"s vote, suggesting that getting out the vote will be crucial. Low turnout has historically favored the Conservatives. Trudeau, at a campaign stop in Windsor, Ontario, on Friday, made a rare concession that a pandemic election was not ideal, but urged supporters to vote despite any misgivings. "I understand the frustration that some people are feeling. They just want things to get back to normal and an election isn"t getting back to normal," he said, as anti-vaccine mandate protesters chanted outside the venue. "It"s a time of choice, it"s a time of decision, it"s a time of stepping up," he said, painting his party as the best choice to end the pandemic, fight climate change and grow the economy. Trudeau, 49, called an early election on Aug. 15, seeking a parliamentary majority after two years of minority government in which he had to work with other parties to govern. But he is now scrambling to save his job. Two senior Liberals with direct roles in the campaign both told Reuters they were worried that Canadians might be more focused on returning to their routines - rather than on politics - and therefore less motivated to vote. The pandemic is intensifying in parts of the country and voters will likely face longer lines than usual on Election Day, due to fewer polling stations and distancing requirements. O"Toole, 48, a former Cabinet minister who has led his party for just over a year, has proved competitive with a disciplined campaign appealing to centrist voters, while avoiding alienating his center-right base. "It"s not about convincing people they should think about voting for you anymore. It"s about getting the people who are committed to voting for you out to vote," said Darrell Bricker, chief executive of Ipsos Public Affairs. "Turnout is going to be everything." The Liberals lead the Conservatives 31.9% to 30.4%, according to the latest election poll by Nanos Research, with the New Democrats in third at 20.3%. Trudeau has slight edge on O"Toole as preferred prime minister, at 29.8% to 27.8%. But opinion polls do not always reflect what happens on Election Night, as turnout can hugely affect seat counts. "If turnout is unusual, we could have many more surprises on Monday night," Philippe Fournier, a polling analyst for the 338Canada.com website, told the Reuters Global Markets Forum on Thursday. CLOSER THAN EXPECTED Trudeau held a comfortable lead in the polls going into the campaign, but that has vanished because of what many voters see as an unnecessary election. He also faces a challenge from New Democratic Party (NDP) leader Jagmeet Singh, 42, who outstrips Trudeau and O"Toole in personal popularity and appeals to the same voters the center-left Liberals need. Singh was endorsed Friday by progressive U.S. Senator Bernie Sanders, a two-time presidential candidate. If enough voters opt for Singh, it could split the progressive camp and allow O"Toole to take power. Trudeau on Friday called on progressive voters to choose Liberals over the NDP to keep the Conservatives from winning. "The Liberal party is not only the only party that can stop the Conservatives, but we"re also the only party with a real plan to get things done," he said. Trudeau"s rallying call was bolstered by former U.S. Secretary of State Hillary Clinton, who on Friday tweeted her support for his progressive leadership. That followed an endorsement by former U.S. President Barack Obama on Thursday. O"Toole, campaigning in London, Ontario, where the far-right People"s Party of Canada (PPC) is gaining traction, jabbed again at Trudeau"s decision to call an election during a pandemic, painting the Liberal leader as selfish and power hungry. O"Toole needs to convince PPC supporters that he is their only hope of getting Trudeau out of office. "We deserve change. And if people vote for anything other than the Conservative Party of Canada for that change, then they"re voting for Justin Trudeau," O"Toole said. Oddsmakers, meanwhile, are betting that Trudeau will indeed win his third election. They give the Liberals an 80% chance of taking the most seats, OddsChecker said on Friday. "We might have done all of this to end up with the same result as last time," said Daniel Beland, director of the Institute for the Study of Canada at Montreal"s McGill University.