It's not just the Greens and the NDP that support a voting system that some perceive to be fairer to smaller parties. Some Liberals are coming on side as well.

Former Liberal Party leader Stéphane Dion is pushing for a form of proportional representation, a system that allocates electoral seats in proportion with the popular vote. Although Fair Vote Canada called Dion the party's democratic reform critic, he was in fact removed by Trudeau from that position.

The traditional first-past-the-post system, or winner-take-all, used in Canadian elections means a political party can win a majority with less than 40 per cent of the popular vote, as the Conservatives did in 2011.

Or it can mean a party that won 32 per cent of the popular vote is shut out of any seats in a province, as happened to the NDP in Saskatchewan in the last federal election.

The Liberal Party's Stephane Dion favours a form of proportional representation voting system. (Adrian Wyld/Canadian Press) When asked Thursday during a news conference if the Liberal Party supported his view, Dion said, "When I speak of moderate proportional representation, it's my personal view, which I'm allowed to express with the support of my former leader Bob Rae."

Dion gave no explanation why he would need the support of a former leader.

Shortly after he resigned from politics this summer, Rae became a member of the national advisory board of Fair Vote Canada, an organizations that advocates for proportional representation.

In a statement on Fair Vote Canada's website, Rae says, “Canadians need to know that their votes will really count. This means moving beyond our first-past-the-post system”.

No support from Trudeau

However, Liberal Party Leader Justin Trudeau said in his leadership campaign literature, "I do not support proportional representation because I believe deeply that every member of Parliament should represent actual Canadians and Canadian communities, not just political parties."

Trudeau favours a preferential ballot, a system used during the leadership campaign, in which voters mark their choices of candidates in a first to last sequence, and each choice is worth a number of points.

That system is not always liked by voters, because a candidate who wins the most votes would not necessarily become the representative for the riding. It can also result in a semi-permanent or even permanent series of coalition governments.

The only other current Liberal MP who supports proportional representation is Joyce Murray who came a distant second to Trudeau during the party's spring leadership race. Proportional representation was part of her platform.

Murray was supposed to be part of a rally Fair Vote Canada staged on Parliament Hill Thursday, but she failed to show up for the sparsely attended event.

A spokesperson said Murray has signed a declaration for the Make Every Vote Count campaign, which is attempting to garner 100,000 signatures asking that some form of proportional representation be a key issue in the next general election.

NDP support for proportional representation 'long-standing'

At Fair Vote's news conference Thursday, NDP Leader Tom Mulcair stated his party's support for proportional representation is “long-standing,” even though the NDP had no trouble tripling its seats in the last election under the first-past-the-post system.

Asked whether he could support the idea of a switch to proportional representation without a referendum, Mulcair said it would be such a "profound" change for Canadians he would start with “a broad-based consultation process" led by a panel of experts. He added he wouldn’t rule out a referendum.

Mulcair said he prefers a "mixed proportional system," using the first-past-the-post system for a "good number of seats" as well as a "balancing approach for some seats."

Dion favours a radically redesigned system, with three to five MPs representing one seat, mixed with preferential voting as well, although the number of ridings would be reduced.

It may be the complexity of various proportional representation schemes that has made voters reject the idea in several provincial referendums.

Green Party hurt most

No party has been more hurt by the first-past-the-post system than the Green Party. Green candidates won a million votes in the 2006 election, but failed to win a single seat.

Former NHL hockey player Georges Laraque is the Green Party of Canada's deputy leader. He's urging other opposition parties to make proportional representation an election issue. (Getty Images)

On Thursday, the deputy leader of the Greens, former NHL hockey player Georges Laraque, urged Mulcair and Dion not to renege on their promises if either of their parties, or perhaps both in a coalition, form a government in 2015.

"If you guys win in this election coming up, will you guys still sign and reinforce the fact that you disagree with the voting system and you will change it?”

Laraque who is running for the Greens in the upcoming byelection in the Montreal riding of Bourassa, added, “Because if you guys don't then we're going round and round with this for nothing."