Sen. Serge Joyal, an independent Liberal and acknowledged constitutional authority, said adopting some form of proportional representation could make majority governments less likely and require two or more parties to come together to form less stable minority or coalition governments.
That in turn could necessitate clarification of the Governor General's prerogative to decide which party leader becomes prime minister and, if a coalition collapses, when to dissolve Parliament.
Governor General David Johnston applauds Prime Minister Justin Trudeau following his swearing-in. (Photo: Adrian Wyld/CP)
And, Joyal noted, any change to the Governor General's powers would require a constitutional amendment approved by all 10 provinces.
"Anyone who will look into, seriously, to really implement proportional representation ... we have to review those things, those powers, because otherwise we will discover suddenly that we have created a nightmare and we won't know how to address it," Joyal told an open caucus meeting held by independent Liberal senators to hear from experts on electoral reform.
Joyal noted that an attempt to form a Liberal-NDP coalition government in 2008 led to a "crisis" in which then-prime minister Stephen Harper persuaded the Governor General to prorogue Parliament to avoid defeat of his minority Conservative government. The propriety of the Governor General's decision has been hotly debated ever since.
Does proportional representation mean less stable governments?
However, York University political science professor Dennis Pilon, who has researched electoral systems around the globe, said it's incorrect to assume that proportional representation (PR) would automatically lead to less stable governments. Indeed, he said Canada's current first-past-the-post (FPTP) electoral system produces more instability than PR systems.
Canada has produced "many more minority governments" than other Westminster-style Parliaments, Pilon said, in part because FPTP encourages political parties to be highly partisan and adversarial. By contrast, he said proportional systems encourage parties to be more collaborative.
Currently, the candidate who wins the most votes in a riding is elected, frequently with considerably less than 50 per cent of the vote. Majority governments are routinely elected with as little as 38 per cent of the national vote.
PR systems aim to ensure a party's share of the vote is more accurately reflected in its share of the seats in the legislature.
Trudeau has promised that last fall's election will be the last conducted under FPTP. His government is preparing to create an all-party committee to examine alternatives, including PR and ranked ballots.
Liberals won't reopen Constitution: Monsef
Democratic Institutions Minister Maryam Monsef said Wednesday that the government has no intention of reopening the Constitution, that whatever it does on electoral reform will be "within the constitutional framework."
The Liberal Senate caucus also heard from former chief electoral officer Jean-Pierre Kingsley, who said electoral reform is long overdue.
FPTP made sense early in Canada's history when there were only two main parties and one of them emerged from elections with more than 50 per cent of the vote, Kingsley said. But it no longer makes sense when there are five or more parties vying for election, all but guaranteeing none will gain true majority support.
Also on HuffPost