OTTAWA, Aug 15 (Reuters) - Canadian Prime Minister Justin Trudeau on Sunday called an early election for Sept. 20, saying he needed a new mandate to ensure voters approved of his Liberal government"s plan to recover from the COVID-19 pandemic. Trudeau, 49, is betting that high vaccination rates against the virus and a post-pandemic economic rebound will help him prolong and strengthen his grip on power. Newly-released data shows 71% of the country"s eligible population is fully vaccinated. The election comes at a "pivotal, consequential moment" for Canada, Trudeau said. "We will be taking decisions that will last not just for the coming months but for the coming decades. Canadians deserve their say. That"s exactly what we"re going to give them," he told reporters. Trudeau spoke after visiting Governor General Mary Simon, the representative of head of state Queen Elizabeth, to formally request the dissolution of Parliament. Polls suggest the Liberals will win their third consecutive election but may not regain a majority in the 338-seat House of Commons. Trudeau currently has only a minority of seats, leaving him reliant on other parties to govern. Nationally, Liberals would win 35% of the vote, compared with 30% for the main opposition Conservative Party and 19% for the left-leaning New Democrats, a Leger Marketing poll showed on Aug. 12. The leader of the Conservatives, Erin O"Toole, criticized Trudeau for calling an election as the country faces a fourth wave of COVID-19, saying it undermines the efforts Canadians took to fight the pandemic. "We shouldn"t be risking that for political games or political gain," O"Toole told reporters. FACTBOX on main parties and leaders, click L1N2PB2W0L1N2PB2IE The Liberals spent heavily on subsidies to businesses and individuals to limit the damage from COVID-19, sending both the national debt and budget deficits to record highs. The Conservatives and New Democrats have in recent days condemned the idea of an early election, saying there was no need for it and describing the call as a power grab. "This is a really important moment," Trudeau said when asked repeatedly why he was calling an election during a pandemic. He said some Conservative legislators had described as "tyrannical" the government"s push to make vaccinations mandatory for federally regulated industries. read more Canada"s Prime Minister Justin Trudeau takes a selfie with supporters during a campaign stop in his Papineau riding in Montreal, Quebec, Canada August 15, 2021. REUTERS/Christinne Muschi Canada"s Liberal Prime Minister Justin Trudeau greets supporters as he arrives at the Marriott hotel before embarking on his first election campaign visit, in Ottawa, Ontario, Canada August 15, 2021. REUTERS/Lars Hagberg Canada"s New Democratic Party (NDP) leader Jagmeet Singh with his wife Gurkiran Kaur Sidhu greet candidates and supporters prior to speaking with the press after Prime Minister Justin Trudeau called an early election, in Montreal, Quebec, Canada August 15, 2021. REUTERS/Christinne Muschi 1/6 Canada"s Liberal Prime Minister Justin Trudeau greets supporters as he arrives at the Marriott hotel before embarking on his first election campaign visit, in Ottawa, Ontario, Canada August 15, 2021. REUTERS/Lars Hagberg "The answer to tyranny is to have an election," he said. The right-of-center Conservatives, the Liberals" biggest rivals, say spending will increase if Trudeau wins again, leaving generations of Canadians hobbled by debt. With a parliamentary majority, Trudeau would have a free hand to follow through on his stated policy priorities of fighting climate change and supporting those who suffered most during the pandemic. "Our planet and our future are at stake. So I need you alongside me in this fight," he said on Sunday. Nanos Research pollster Nik Nanos said the Liberals had no choice but to go to the polls now, noting that the longer they wait, the more risk they face of a fourth wave of the coronavirus. "They see a window and they"re going to shoot for that window before the bad news comes out, before there"s another variant or before the bill shows up for the full cost of fighting the pandemic," he said in an interview. The Bank of Canada last month painted an optimistic picture of growth heading into the second half of the year. But the bond market already is signaling that the pace of Canada"s economic growth could slow as Delta variant cases rise in the United States, its largest trading partner, and in some other major export markets. read more "RISKY SITUATION" Trudeau, the son of longtime former Prime Minister Pierre Trudeau, first won a majority in 2015. But in the 2019 election, after decades-old black face pictures surfaced, he came up short of a majority. Another minority administration would leave him likely relying once more on the New Democrats, who favor even heavier spending on social programs. It would also raise questions about Trudeau"s future as the leader of his party. Trudeau repeatedly refused to say on Sunday if he would resign as leader if he does not secure a majority in the vote. Without a strong opponent to rail against in this election, as the main opposition Conservatives struggle, the Liberals fear the vote may fragment and hand them yet another minority government. read more Some Liberals question the need for an early election, saying that although Trudeau had complained about obstructionism from opposition parties, he managed to pass most of the legislation the Liberals proposed. "It"s a risky situation to go the polls when you don"t have to," said Peter Donolo, a political strategist at Hill+Knowlton Strategies and communications director for former Liberal Prime Minister Jean Chretien.