Justin Trudeau 

Canadian Prime Minister Justin Trudeau's main rival Andrew Scheer of the Conservatives came out swinging against the Liberal incumbent in an election debate on Monday after a dismal week that saw him blow a previous matchup.

The televised grudge match brought together on stage a record six party leaders.

But the main focus stayed on the two front-runners who are in a dead heat with only two weeks left before the October 21 ballot. Each is looking to sway a big block of undecided voters.

From the get-go, Scheer went on the attack, calling Trudeau "a phoney and a fraud." 

He raised Trudeau's wearing of blackface makeup, his meddling in the criminal prosecution of engineering ­giant SNC-Lavalin and his firing of the nation's first indigenous attorney general "for not going along with his corruption." "You do not deserve to govern this country," he said.

Trudeau shot back, criticizing Scheer for his underwhelming climate proposals at a time of global crisis, while defending his record over the past four years in office - including a strong economy, less poverty and low unemployment.

He also accused Scheer and his ­Tories of fostering "politics of fear and division."

Scheer, who is untested and relatively unknown after only two years as leader of the Conservative Party, has struggled to endear himself to voters in this campaign. After being a wallflower in the first debate in French, which he is less comfortable speaking than English, he found himself on the back foot as questions about his dual American-Canadian nationality - revealed only Thursday - overshadowed his policy announcements.

In cosmopolitan Canada, it is no impediment to high office to have roots in other countries, but Scheer sparked ­anger by leaving it so late in the campaign to front up with the public.

Critics also highlighted what they saw as a double standard. He and fellow Tories in past elections attacked leaders of the Liberals and New Democrats as well as former governor general Michaelle Jean because of dual citizenship.