TORONTO -- Justin Trudeau invoked Liberal governments of the past -- including the legacy of his famous father -- as he went on the offensive against his Conservative and NDP rivals in Monday's Munk debate on foreign affairs.

Trudeau pointed to peacekeepers, spearheaded by Lester Pearson, as a symbol of what Canada can do on the world stage.

He credited his father Pierre Trudeau with the creation of the Charter of Rights and Freedoms and official bilingualism, and at the same time managed to get in a shot at NDP Leader Tom Mulcair.

"When we talk about the legacy that my father leaves behind, first and foremost is the Charter of Rights and Freedoms, which has defined Canada as a country that stands up for individual rights -- even against governments that want to take those away," Trudeau said, slowing down for emphasis.

"Multiculturalism, that has made Canada strong not in spite of its diversity, but because of its diversity -- and bilingualism, which as my father understood, Mr. Mulcair, means saying the same thing in French as you say in English."

That last remark -- a reference to charges throughout the campaign that the NDP leader has been massaging his message when speaking in Quebec -- evoked laughter and applause from an audience instructed to keep quiet.

Trudeau later said that he raised the issue of his father Monday because of the date: Pierre Trudeau died on Sept. 28, 2000, at the age of 80.

"He was obviously on my mind and I was happy to talk about him as a son who loves his father very, very much," he said.

For most of the night, Trudeau was chippy and aggressive, frequently interrupting Conservative Leader Stephen Harper.

In one particularly compelling exchange, he tried for almost a full minute to talk over Harper on the topic of whether terrorists should lose their Canadian citizenship. "Let him talk," one audience member shouted.

Trudeau got another burst of applause when he accused Harper of scaring Canadians.

"Mr. Harper ... wants us to be afraid that there's a terrorist hiding behind any leaf and rock around us, and we all need to be afraid."

More chuckles ensued when Trudeau accused Harper of being "big sled, no dogs" on Arctic issues.

Trudeau tried to remain on offence, although he was criticized by Mulcair for supporting Bill C-51, the government's anti-terrorism legislation, in the House of Commons. He was also criticized by Harper for opposing the idea of stripping terrorists of their citizenship.

Many observers expected the debate to be a challenge for Trudeau, the least experienced politician on the stage and one whose foreign-policy pronouncements -- the focus of Monday's debate -- have been mocked as sophomoric in Conservative attack ads.

The Conservatives tried earlier in the day to put Trudeau on the defensive by leaking a recording of comments he made earlier this year in which he opposed stripping terrorists of their citizenship.

The Liberal leader doubled down, however, saying Harper's plan would create a "slippery slope" that could see other less deserving Canadians stripped of their citizenship.

But while Trudeau landed more than a few square blows, he took his share on the chin as well.

When he promised to take a tough stance with Russian president Vladimir Putin if elected prime minister, Mulcair shot back.

"It's interesting to hear Mr. Trudeau say what he's going to do with Mr. Putin -- Mr. Trudeau, you can't even stand up to Stephen Harper on C-51," the NDP leader said, eliciting a cheer from the audience.

"How are you going to stand up to Putin?"