In a telephone interview with CBC News, Trudeau said a Liberal government would move to reverse the Conservatives' proposed measure to allow income splitting for families with children should they make good on their promise to introduce it when the deficit is paid off.
Here is a partial transcript of the interview, edited for length and clarity.
On reversing Stephen Harper's tax relief measures
Q: You have said you would reverse the government's decision to raise the age of eligibility for Old Age Security. You have also left the door opened to reversing other tax measures. What specifically are you looking at?
"We've been talking about the income splitting measure that the government has proposed recently. No credible think-tank across the country on an economic level has said that this is actually is a good program. It doesn't help the people who need it most and it costs Canadians an awful lot to do. It doesn't make sense. We've said throughout our propositions that we will do things that are focused on growing the economy and creating jobs and helping middle-class Canadians succeed. And that's a lens we will apply extremely consistently to everything put forward....
Voter support for the Liberals
While Trudeau continues to come under fire for a perceived lack of substance, he has said he is working on developing the party's platform in time for the next election campaign. "I'm not going to cut short any of the really important conversations we have to have as we build the plan to govern this country," he told CBC News.
Q: Some polls are starting to suggest that support for you is softening. Is there a risk you are ceding the room to your rivals?
"I think one of the things we've seen over the past months and years in this country, is the polls come and go, up and down. What matters is the engagement that you have on the ground with people and I'm really, really proud and encouraged by the kinds of responses that we've gotten across the country to whether it's by-elections, whether it's fundraising, whether it's how our membership numbers are coming. That's the essential thing for me and that's what we're very much focused on."
On his party's pro-choice position
Q: You write that you're confident that your dad, a devout Catholic, would agree with your pro-choice position. Do you think that would come as a surprise to people in your party or even the Church?
"Well, first of all the position comes from the party. In 2012, the Liberal Party affirmed overwhelmingly at the policy convention that we are a pro-choice party. It means that we are a party that defends women's rights and therefore it would be inconsistent for any Liberal MP to be able to vote to take away women's rights. And I think that's the essence of the Liberal Party of Canada. We defend people's rights."
Q: The next time the issue does come up in Parliament, will it be a free vote?
"The Liberal Party will not vote, no Liberal member of Parliament will vote, to take away a woman's right to choose."
Q: So it will be a whipped vote?
A: "Oh, very much so. I have been consistent that we need a lot more free votes but on things spelled out in our platform, on matters of budget confidence, and on things that go to the heart of the Charter of Rights and Freedoms, Liberal members of Parliament will be expected to be Liberals."
On his handling of the ISIS debate
In his memoir, Trudeau writes that he learned how to make decisions by watching his dad asking questions and challenging the opinion of those around him. This collaborative approach, as he calls it, to decision-making is something Trudeau says has informed his own leadership style.
Q: Is this an approach you used to arrive at your position on the ISIS mission?
"That was very much the process because we sat down as a caucus and had a very, very robust decision, discussion on what Canada's role should be in the fight against ISIS. We all agree that Canada needed to have a role to play, Canada needed to be part of the coalition. But we also agreed that Mr. Harper had demonstrated no interest or even capacity in elaborating and explaining, in justifying why airstrikes were the best way for Canada to help. We much preferred to support, as we did, a military mission for 30 days that was a non-combat mission, training and supporting local troops on the ground who were taking the fight to ISIS where it matters most. And at the same time needing to reinforce the things that Canada has traditionally done very well in humanitarian support and refugees.
Q: You say Stephen Harper didn't make the case for airstrikes but you too have been criticized for your handling of the issue, whether it was handing off the debate the following week to Marc Garneau or as some have said over the weekend that Jean Chrétien had to come to your rescue on Friday. How would you rate your own performance?
A: "I'm very pleased with the position we took and how we went about it. And about surrounding myself with strong people, I understand people are focused on the Stephen Harper school of leadership, which is he only takes advice from the person he sees in the mirror every morning and he does not want anyone strong around him. On the contrary, I'm incredibly proud of having someone of Marc Garneau's calibre and military experience, who just returned from a trip a month before to northern Iraq, to be able to weigh in on that.
"As you may remember, I had two big speeches on that just the week before,so I felt that ... my best contribution to this debate was very much by supporting the thoughtful and strong approaches of my fellow Liberals while asking questions and knowing that my speeches were very much on the record as well."
Q: Prior to the vote you said you had consulted other party elders. It turned out some of them later made it known they disagreed with your position. What was it about their arguments that did not convince you to see it their way?
"I have a tremendous amount of respect for every previous Liberal leader and they all came with a different reality but much of it is always tinged with politics and I wasn't so much interested on the (inaudible) politics of this. I was very much focused on making sure that Canada's position is the right one for the long term. And that's where crossing the line from a non-combat mission into a combat mission is a decision that has to be taken very, very carefully and [responsibly]. And to be quite frank about it, the prime minister did not take that aspect of it very seriously. He preferred to play politics..."
On renovations to 24 Sussex
Q: 24 Sussex has been in dire need of repairs for several years now. Former auditor general Sheila Fraser said in 2008 that renovations would take at least 15 months to complete and costs at least $10 million. If you become Canada's next prime minister, would you vacate 24 Sussex to allow for renovations to take place?
"I'm going to listen to the experts at the National Capital Commission and others who will say what is needed in this situation. I'm certainly not going to try and second guess people who have been waiting a long time to do some repairs to a house that is apparently, as you say,in poor shape. I think we need to respect various elements of our heritage and that's where I will defer to the experts who actually run that house."