Prime minister-designate Justin Trudeau may have campaigned on electoral change, but political scientists say he may want to rethink that promise now he has a majority government.

The "first-past-the-post" system Canada currently uses has been criticized by voters and politicians alike for years.

In recent months, Trudeau promised 2015 would be the last federal election where the number of seats wins, as opposed to the percentage of the popular vote.

But that was before Trudeau's landslide win.

UBC political science professor Max Cameron says the Liberal majority is a direct consequence of the way Canada's electoral system works. 

"A majority, I think, in an interesting way gives the Liberals the means to make change but paradoxically, at least in this respect, diminishes their motivation," said Cameron at a UBC roundtable on the federal election results.

"It gives them many, many more seats than they got in terms of percentage of the popular vote. In some sense, they've got not a lot to gain from changing the current system."

The Liberals won less than 40 per cent of the popular vote but 54 per cent of the seats. 

Seats elected and share of popular vote

As shown here, the Liberals won more than half the ridings in Canada, thus achieving a majority government with only 39.5 per cent of the vote. (CBC)

Cameron says if seats were allocated in proportion to votes, the Liberals would have won closer to 135 seats instead of 184.

House-of-Commons-after

A breakdown of seats by party in the House of Commons. Under proportional representation, these seats would be allocated to reflect how individuals voted, rather than by riding. (CBC)

'Moral imperative to fix system'

Political science PhD candidate David Moscrop says he thinks the Liberals owe it to their supporters to try to fix the system.

"I think the Liberals have a moral imperative to pursue it now," he said. "They said it at the start. They were very clear. They attached a timeline of 18 months."

In both British Columbia and Ontario, a citizens' assembly on electoral reform has already investigated changes to the provincial electoral systems.

Cameron says the Liberals could draw lessons from those about the best way to proceed with change.

Electoral change doesn't require constitutional change but there needs to be public support. 

In both provinces, the Citizens' Assembly proposed replacing the province's existing first-past-the-post system — each with different plans — but voters rejected the ideas.

Chance for something innovative?

UBC political science professor Richard Johnston is extremely skeptical about the likelihood of any federal electoral change under the Liberals.

He says, B.C. and Ontario made "recommendations for proportional representation but, in the end, we have the same electoral system as before."

The Liberal Party of Canada has not indicated what type of proportional representation it would want, but Cameron says there's a real opportunity for Canada to do something innovative. 

He also says, "opposition parties tend to talk a lot about democratic reform when they're in opposition and rarely deliver once in government."

In his victory speech highlighting most of his campaign promises, Trudeau didn't mention proportional representation.

However, when asked about the issue by a francophone journalist in a news conference the day after the election, he responded, in French, saying the Liberals had committed to making this the last election to use first-past-the-post.

He added there was much work to do, consulting Canadians and examining the issue.

election results

Under first-past-the-post, the map shows Canada awash in a sea of red — even though more people voted against the Liberals than for them.