After a debate in which he was once again in the crosshairs of his Liberal leadership opponents, Justin Trudeau’s campaign revealed that he has lured 150,000 new supporters to the party.

Sunday marked not only the day candidates hoping to take the helm of the Liberal Party of Canada engaged in their fourth, and second-to-last, debate. It was also the last day for candidates to sign up supporters, who will also vote for the next leader in addition to card-carrying members.

Despite the big number, Trudeau dismissed suggestions he could win on the first ballot.

“People can say all sorts of different things, because the fact is it’s never been done this way before,” he told CTV News.

The numbers were released hours after candidate Marc Garneau targeted Trudeau during Sunday’s debate in Halifax, accusing the perceived frontrunner of avoiding the big-ticket platform issues. 

“I believe that Canadians want to see substance. They don’t want empty words,” Garneau said to Trudeau. “They may not like what I have to say, but at least they will know where I stand.”

Trudeau said he’s proud of the high-level, positive campaign he’s running, and he’s been “just as specific” as the other contenders. He said Liberals know his views on a number of issues, including his support for the legalization of marijuana and his opposition to the Northern Gateway oil pipeline.

Trudeau and Garneau took turns attacking Joyce Murray’s proposal to work with the New Democrats and the Green Party to oust the ruling Conservatives in the 2015 election.

Trudeau said making a deal with the NDP ruins a positive approach established when new supporters join the party.   

Murray told Trudeau if he was “listening to Canadians, you would be going after proportional representation.”

Garneau pressed Murray on how she would form an alliance with NDP leader Tom Mulcair.

Murray said she is proposing a “one-time co-operation.”

"Kind of like a Canadian hockey team coming together in the Olympics in 2010 and winning gold and then going back and competing with each other once again,” she said.

Contender Martin Cauchon also reiterated his opposition to a merger with the NDP. 

“If they ever merge with a party, I believe it’s going to be with the Bloc Quebecois,” he said.

He pointed to Claude Patry’s defection last week from the NDP to the Bloc.

A final debate will be held March 23 in Montreal before the Liberal leadership convention scheduled for April 14.

With a report from CTV’s Daniele Hamamdjian

Replay the live blog below: