Prime Minister Justin Trudeau says he has no interest in replacing Canada's first-past-the-post electoral system with one designed to favour the Liberal party.

Rather, he says he wants a system that makes the country's democracy stronger.

"I guess it comes down to why am I doing this job?" Trudeau told The Canadian Press.

"Am I in this job to defend a particular political party and ensure that, you know, Liberals get to run this country forever? No. I'm in this job to try and make a significant, positive difference in people's lives."

If his only concern was benefiting his own party, Trudeau said the easiest thing to do would be to maintain the status quo, which allowed the Liberals to capture 54 per cent of the seats in the House of Commons on Oct. 19 with just 39.5 per cent of the popular vote.

Campaign promise for change

"It would be easier to do nothing and sit back and just say, 'Okay, you know what, this worked for us, I think we can make this current system work for a few more mandates' ... But that's not the kind of leadership that Canadians expected."

Trudeau promised during the campaign that the Oct. 19 election would be the last run under first-past-the-post (FPTP), where the candidate with the most votes in a riding wins the seat. The system has been criticized for producing false majorities — including Trudeau's — and under-representing smaller parties, thereby contributing to low turnout because many people feel their votes don't count.

The newly minted prime minister gave the most detailed explanation yet of his thinking on electoral reform during a 75-minute sit-down with the Ottawa bureau of The Canadian Press. In the wide-ranging session, he also:

Flatly asserted there is no need to reopen the Constitution to finally secure Quebec's signature on the document.

Defended his approach to staying connected with Canadians who don't pay close attention to politics, including posing for selfies and giving interviews to non-political publications like fashion bible Vogue magazine.

Defended his commitment to withdraw Canadian fighter jets from the U.S.-led bombing campaign against Islamic militants in Syria and Iraq, reiterated his vow to find other ways to contribute to the allied fight against terrorists, including training local forces, but expressed wariness about having Canadian military trainers get close to the frontlines.

Since the election, the Conservatives have accused Trudeau of wanting to replace FPTP with a ranked ballot system — without consulting Canadians through a referendum — because it would benefit the centrist Liberals who would be most likely to be picked as the second choice by supporters of other, more ideological parties.

Under ranked or preferential balloting, voters indicate their first, second, third and subsequent choices. If no candidate wins a clear majority, the last-place contender is dropped and his or her supporters' second choices are counted. That continues until one candidate emerges with more than 50 per cent of the vote.

Personal preference for ranked ballots

During the Liberal leadership race, Trudeau expressed a personal preference for ranked balloting. But he told The Canadian Press he wants to be "careful about pushing my own views on this" now that they carry greater weight.

In any event, he said the shape electoral reform ultimately takes won't be entirely up to him. Canadians will be "broadly consulted" by a special all-party committee that is supposed to recommend a replacement for FPTP within 18 months. He did not rule out an eventual referendum on the matter, although that route has killed electoral reform initiatives in three provinces.

That said, Trudeau said he feels "very strongly" that a reformed electoral system should not weaken a member of Parliament's connection with and accountability to constituents in a specific riding.

Prime Minister Justin Trudeau has promised the 2015 federal election will be the last under a first-past-the-post system. (Patrick Doyle/Canadian Press)

"The fact that every single politician needs to earn the trust of a specific group of constituents who cover the broad range of Canadian public opinion strengthens our democracy," he said.

"I'm wary of disconnecting any MPs from specific groups of citizens or geographic location. I think that's one of the strengths of our parliamentary system and as soon as you get into lists by parties or groups you have people who owe their election to the House of Commons to a partisan organization rather than to a group of Canadians."

That would seem to rule out mixed member proportional representation, a reform favoured by the NDP and in use in Germany and New Zealand, among other countries. Under that system, MPs would be elected in each riding but they'd be augmented by MPs chosen from party lists in proportion to each party's share of the popular vote.

Critics of ranked balloting argue that it does not, in itself, ensure that a party's representation in the Commons more accurately reflects its share of the vote. Indeed, some analyses of the 2015 election results have suggested that the Liberals — the most popular second choice for both Conservative and NDP supporters — would have secured an even more lopsided majority under ranked balloting.

However, Trudeau said any election held under FPTP is a "very poor predictor" of how voters would behave under a different system.

Need 'mature discussion'

Indeed, it's conceivable that people who voted strategically for the Liberals on Oct. 19 to defeat Stephen Harper's Conservatives may have been more inclined to stick with the NDP or Greens if they knew they could mark the Liberals as their second choice.

Trudeau said the real question that needs to be answered is: "What kind of political discourse do we want to have in Canada?" In that vein, Canadians need to have a "mature discussion" about various electoral systems and their potential for such things as producing stable governments or more collegial politics with less partisan conflict or for augmenting the representation of minority or single-issue groups.

"Deciding what kind of country we are and what kind of system would suit us is actually a pretty exciting thing. It's a very daunting task because it's the kind of thing that, yes, will have an impact for decades."