Justin Trudeau addresses internal and external attacks at Liberal debate

The remaining eight Liberal leadership candidates convened in Halifax on Sunday afternoon for their fourth of five debates.

The topics included the rural-urban divide, defence, health care, daycare, and women's issues. But, as in the previous debates, the most raucous discussions involved Joyce Murray's idea for cooperation with the NDP and Justin Trudeau's apparent lack of substance.

In this debate, Trudeau responded to attacks against him by going on the offensive — accusing 'some' (most likely Marc Garneau) of running a negative campaign.

[ Related: Liberal leadership candidate Marc Garneau challenges Justin Trudeau to a one-on-one debate ]

"The Liberal Party lost it's place and lost it's way because people were tired of the party turning on each other," Trudeau said during his one-on-one debate with Garneau.

"And that's why the top-down backroom heavy negative campaign that has been run by some other people in this campaign is something I don't think Liberals want to see."

Trudeau added that he has spoken about specific policies during the past several months, citing his positions on the Northern Gateway pipeline, foreign investment and the legalization of marijuana.

In his closing statement, Trudeau addressed attacks from the Harper government.

[ Related: Immigration Minister Jason Kenney goes on the attack against Justin Trudeau ]

"Because we've been successful as a party over these past months at drawing interest and drawing energy, the attacks have started," Trudeau said.

"People encourage me by saying 'you know what, don't worry about it, it's just Stephen Harper being afraid of you.'

"And I say no, Stephen Harper is afraid of engaged, empowered active citizens. Stephen Harper's not afraid of me. He's too busy being afraid of you. That's what we're doing together."

[ Related: Polling analysis suggests Liberals are on the rebound, Tories are slipping ]

Sunday was the cut-off date for anyone who wanted to sign-up as supporter for the party so it was critical for all the candidates — sans Trudeau — to either get a knock-out punch against Justin or to really stand-out from the crowd.

As was the case in the other debates, however, none of them did.

The final debate is schedule for March 23rd in Montreal.

The Liberals choose their new leader (most likely Justin Trudeau) on April 14th.

Post debate analysis on Twitter by some of Canada's political journos:

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