Canadians head to the polls Monday to elect a new Parliament as scandal-scarred Prime Minister Justin Trudeau tries to avoid being knocked out of power after one term — as polls predict that his Liberal Party will at least lose its majority.

The Liberals and the Conservatives — led by Andrew Scheer — could be set for a near dead heat in what pundits are calling one of the nation’s closest elections ever.

Neither of the two parties is forecast to garner enough support to secure an absolute majority of seats in Parliament.

Trudeau, the 47-year-old former golden boy, rode the star power of his father, liberal icon and late Prime Minister Pierre Trudeau, when he won in 2015 — but his prospects for another term have been damaged by a combination of scandal and high expectations.

Polls indicate his Liberal Party may have to rely on an opposition party to remain in power. Not in 84 years has a first-term Canadian prime minister with a parliamentary majority lost a bid for re-election.

In 2015, Trudeau reasserted liberalism after almost a decade of Conservative Party government, but he is one of the few remaining progressive leaders in the world.

Perhaps sensing Trudeau is in trouble, former President Barack Obama weighed in by urging Canadians to re-elect Trudeau and saying the world needs his progressive leadership now.

But last month, old photos of Trudeau in blackface and brownface emerged, casting doubt on his judgment. His image also was tainted by ethics lapses in the handling of the bribery prosecution of an engineering giant.

During campaign stops in westernmost British Columbia on Sunday, Trudeau made an emotional appeal to voters to give him a chance to build on the achievements of his first term.

He warned against Scheer’s promised rollback of environmental protections, including a federal carbon tax that discourages the use of large amounts of fossil fuels.

“We need a strong, progressive government that will unite Canadians and fight climate change — not a progressive opposition,” Trudeau told a rally in a suburb of Vancouver after stops in Ontario, Manitoba and Alberta.

“We need to unite as citizens. We need to unite as a planet.”

If Trudeau manages to remain in power, it will be because Scheer has struggled to win over voters with his bland, minivan-driving dad persona and a throwback to the thrifty policies of previous Tory administrations.

Canadians “cannot afford” a Liberal government propped up by the third-place New Democratic Party, Scheer said at the end of a last-minute push across the country.

“We can only imagine what the NDP’s price would be to keep Justin Trudeau in power,” he said. “Whatever it is, we know Trudeau would pay any price to stay in power and he’d use your money to do it.”

With Post wires