British Columbia has had several experiments with forms of electoral reform.

The first, in 1952, led to a minority government and was abolished the following year. More recently, the province held two referendums on switching to preferential balloting. Both failed and there has been little appetite since to revive the issue.

But this week's extraordinary election result, which has led to a possible hung legislature with the Green Party holding the balance of power, could force the issue back onto the agenda, as the Greens, who have the most to gain from changing the voting system, consider what to demand from the other parties in exchange for their support.

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And on that issue, the Greens appear to have the most common ground with the NDP. Both parties have promised to change the voting system to a form of proportional representation, though neither has outlined just what that would look like.

"Parties of the left are in power for something like twice as much under a proportional representation kind of system," said Richard Johnston, a political science professor at the University of British Columbia.

In this week's election, the Greens had 16.7 per cent of the popular vote but its three victories represent just 3.4 per cent of the seats in the legislature.

Fair Vote Canada, a grassroots multipartisan citizens' campaign, has called on the Greens and NDP to form a coalition to enact electoral reform.

"We see the situation in B.C. right now as a historically rare opportunity," Fair Vote Canada president Réal Lavergne said. "When you get a minority situation with two parties advocating proportional representation with 57 per cent of vote, you have to seize that."

Green Party Leader Andrew Weaver has not said what concessions he would be seeking from the other parties to secure his support in the legislature, though he has noted that proportional representation is one of his party's top priorities.

The party hasn't determined the specific type of proportional representation it would switch to, but it would create a panel of experts to determine that. The Greens want to switch the electoral system without a referendum.

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"We would implement form of proportional representation without a referendum, that's the difference between us and the NDP," said Jillian Oliver, press secretary for the BC Greens.

The NDP would hold an electoral-reform referendum, but have promised to support the "yes" side.

"This is an exciting time," BC NDP deputy director Glen Sanford said. "When all the ballots are counted, I think the parties need to sit down and fix our voting system and bring more fairness to way we vote."

Complicating matters is the fact that absentee ballots have yet to be counted, meaning close races could change at the end of the month and alter the makeup of the legislature. If the Liberals are elevated to a majority, the Greens would have far less influence.

First-past-the-post electoral systems, which both B.C. and Canada use, ensure that each region of the country with its distinct personality is represented in government. But first-past-the-post can also create false majorities, where a minority of the popular vote can result in a majority of seats. In the 1996 B.C. election, the party with the most votes did not form government.

British Columbia has already had two referendums in 2005 and 2009 on a system called single transferrable vote. In such a system, voters rank candidates in their ridings; if their top candidate wins with more votes than they need or is out of contention, their other choices are distributed to the remaining candidates.

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Both of the referendums failed, although the one in 2005 came close to the 60-per-cent threshold needed to pass.

Prince Edward Island also had a referendum on electoral reform last year that failed.

B.C.'s last minority government elected in 1952 happened under an Alternate Vote system. It allowed voters to rank candidates on their ballots, but was not a proportional representation system. That system was used in two elections – 1952 and 1953 – before the province reverted to first-past-the-post.

Federally, Prime Minister Justin Trudeau's Liberals also campaigned on a platform of electoral reform, but the government has since abandoned that promise.