Liberal Leader Justin Trudeau has defended his recent admission about smoking marijuana in a speech before hundreds of local supporters at his party’s summer caucus in Prince Edward Island.

In a Wednesday evening speech, Trudeau acknowledged the controversy he set off last week. He disclosed in an interview that he smoked marijuana about three years ago, while he was an MP, at a dinner party he was hosting and that he's done that about five or six times in his life.

Earlier in the summer, Trudeau said he wants to see pot legalized, not just decriminalized. The Liberal party voted for that position at its last policy convention.

Trudeau told the huge crowd at the outdoor party held at local Liberal MP Lawrence MacAulay's home that the debate he set off "blew my mind."

"Only in Stephen Harper's Canada could people actually argue that being honest was a calculated risk," said Trudeau. He said he didn't talk about his past marijuana use because he wants to disclose "every little last detail, the public sphere is not supposed to be Oprah," but rather because of the position he backs when it comes to legalization.

"But I do believe that since I am taking a strong policy position on what is a mistake in our policy and in Stephen Harper's Canada that criminalizes hundreds of thousands of people needlessly and costs us hundreds of millions of dollars every year, I think its time to be able to be forthright and honest about the kinds of changes we need to bring," he said.

Trudeau took a few shots at Harper during his speech, calling him "unambitious" and accusing him of having no vision for Canada.

Trudeau mingled with the crowd before his speech, shaking hands and posing for photos, as a band entertained the crowd and people lined up for BBQ'd hamburgers.

Back to Ottawa

Earlier in the day, MPs decided at their caucus meeting to head back to Ottawa in three weeks even though Harper said last week that he wants to ask the Governor General to prorogue Parliament, and plans to return in October with a speech from the throne. Parliament won't sit until after the throne speech, which hasn't yet been scheduled.

Trudeau said MPs will be on Parliament Hill even if the House of Commons isn't sitting, and will meet with stakeholders, do the kind of work normally done at committees, work on developing policies and holding Harper's Conservatives accountable for "erroneous decisions and its poor judgment."

Liberal Leader Justin Trudeau, left, gives opening remarks at the party's caucus meeting in Roseneath, P.E.I., on Wednesday. Francis Scarpaleggia, the caucus chair, is seated next to Trudeau. (Meagan Fitzpatrick/CBC )

The Liberal leader said Canadians expect MPs to be back at work in Parliament in a few weeks and the Liberals won't disappoint them.

"The Liberal Party will be returning in the third week of September as expected, to get to work serving Canadians through the work in Ottawa that they expect us to do," he said.

Trudeau said the Liberal caucus spent much of their morning session discussing transparency and issues affecting the middle class, which is sure to be a primary battle ground in the next election in 2015.

The party is looking to take back some of the ground lost to the Conservatives and NDP over the past few years, in part by bringing in a fresh face to handle fundraising.

Speaking to reporters following the morning meetings, Trudeau said the party is looking for solutions to help young Canadians who can't find jobs, and the parents who have to support them for longer than in past years.

But, pressed for specific details on how to help young people get jobs and assist the middle class, Trudeau said the party needs to consult Canadians and experts.

"This is not something to take lightly, this is not something to reel off because people want answers," he said.

Wealthy Montreal businessman Stephen Bronfman, the party's new chief revenue officer, told reporters at the Liberals' caucus meeting in Prince Edward Island that his goal is get Justin Trudeau elected prime minister. (Meagan Fitzpatrick/CBC News)

Trudeau said he has a responsibility to put forward a robust platform for the next election in 2015, and he's not going to cut the policy development process short just because people may be getting "impatient." Liberals want to provide a good government for Canadians and aren't worried about dominating headlines, he said. They are going to take their time developing policies in preparation for the next election, said Trudeau.

Expenses will be online

Party members also spent part of their day talking about the commitment Trudeau made in the spring for the hospitality and travel expenses of Liberal MPs and senators to be posted online. He said that will start in late September and they'll use the model followed by cabinet ministers.

"I think Canadians demand a level of transparency from their governments and from their political parties that the Liberal Party is happy to step up to, and happy to take the lead on," Trudeau said.

"I know that the other parties will not take long to realize that they cannot operate in secrecy anymore from Canadians."

There was a new face in the Liberal caucus room Wednesday — Montreal businessman Stephen Bronfman. He's been named the party's new chief revenue officer, which puts him in charge of fundraising.

The Bronfman name is one of the biggest in Canadian business — Stephen Bronfman's grandfather built the Seagram liquor empire, making the family billionaires.

Bronfman runs the private investment firm Claridge Inc., and is a longtime family friend of Trudeau. Bronfman was one of the key players in Trudeau's leadership campaign, helping to bring in more than $2 million, and now he has signed on to help the whole party.

Bronfman told CBC News that he's excited for his new role and that in order for the party to be successful in fundraising, it needs to give Canadians a reason to donate.

"I think Justin is a reason but in this day and age, you have to offer more, so we have to rethink the way we do certain things," Bronfman said. The party has to build on what it's doing well but also do things differently, he added. "I think we're bringing a different group of people, a different level of professionalism. We've learned from the past and today is a new day. We've got a big job to do and I think everyone's pretty jazzed up to do it."

The Conservative Party of Canada is a well-oiled fundraising machine, and Bronfman said he knows the Liberals have their work cut out for them to compete at their level. But there are a lot of committed Liberals across the country, he said, and Trudeau is "able to light their fires."

Online fundraising a growth area

A quarter of Trudeau's leadership campaign donations were raised online, and Bronfman said that's a growth area that needs investment. While donating online might appeal more to younger Canadians, Bronfman said the party will try to raise money from all demographics.

"The older Canadians have been amazing, they vote, they give. I think what we're able to do is we're able to tap into younger Canadians and then sort of blend it in," he said. "We've got work to do on all fronts: young, middle, old. We've got to get them all. It's a big country, it's a big fight and we're ready to do it."

Speaking to reporters Wednesday, Bronfman said the party is "staffing up" and working hard to catch up to the Conservatives, a party with a "very solid machine." His is a volunteer position but the party will be hiring a full-time staff person to execute Bronfman's ideas.

"We're going to build this and I know we're going to be successful," he said with confidence. He said Canadians are interested in finding out more about Trudeau and "sticking with it and they're following him and in turn we're getting them to support him."

"The goal is to raise a lot of money and to help Justin become the next prime minister. Simple goal," he said.