The Liberal leader vowed Wednesday that, should he become prime minister, he would repeal the sweeping bill "in its entirety" because it is "bad for democracy, it is bad for Canada."
The NDP, which has been leading the parliamentary charge against the reforms, declined to make the same promise, choosing to remain "focused on stopping this bill right now," in the words of Craig Scott, the party's democratic reform critic.
NDP Leader Tom Mulcair continued that effort in the House of Commons. He threw Prime Minister Stephen Harper's own words back at him to contend the bill is "fit for a Third World dictatorship" and derided the minister responsible for it, Pierre Poilievre, as "a lightweight."
But Wednesday's political fireworks did no more to move the government than did all the electoral experts, federal and provincial, domestic and international, who have to date almost unanimously panned the Fair Elections Act.
"The government has brought forward important modifications that we believe have the support of the Canadian people, in particular the idea that one should not vote without being able to produce any ID whatsoever," Harper told the Commons.
"We are strongly committed to this legislation."
Harper ignored Trudeau's call to allow a free vote on the bill.
The Liberal leader effectively urged Conservative backbenchers to defy party discipline.
"I'm calling on Conservative members of Parliament to stand up for their constituents, to stand up for Canadians, to stand against their leadership and vote in a free vote against this terrible piece of legislation," he said outside the Commons.
Tory backbenchers, however, do not appear inclined to buck the party line. As they emerged from a Conservative caucus meeting Wednesday, MP after MP pledged enthusiastic support for the bill.
"I love the bill the way it is," said Toronto-area MP Costas Menegakis.
Experts, including chief electoral officer Marc Mayrand, have said the bill could disenfranchise tens of thousands of voters; slow investigations into breaches of election laws; give an unfair financial advantage to rich, established parties; seriously erode the independence of the elections watchdog agency; and undermine the faith of Canadians in the fairness of the electoral system.
The government has limited Commons debate and refused to hold cross-country hearings on the bill as it pushes to have it enacted by the time Parliament recesses for the summer in late June.
Mulcair dredged up a 1996 quote from Harper who, as a Reform MP, railed against the Liberal government of day for limiting debate on changes to the Canada Elections Act — reforms his party actually agreed with in principle.
"Using time allocation for electoral law, doing it quickly and without the consent of the other political parties, is the kind of dangerous application of electoral practices that we are more likely to find in Third World countries," Harper said then.
Mulcair asked the prime minister whether he still stood by his 1996 statement.
Harper did not acknowledge his former views or directly respond to Mulcair's question. He posited that most Canadians "clearly believe" it's appropriate to require voters to produce ID and urged opposition MPs to listen to them.
Noting that Poilievre ruled out cross-country hearings on the bill as an "expensive circus," Mulcair accused the prime minister of "talking out of both sides of his mouth."
"On one side he says listen to Canadians. On another side he sends this lightweight to give his answers for him."
Opposition MPs also continued to demand that Poilievre apologize for attacking the integrity and impartiality of chief electoral officer Marc Mayrand, an independent officer of Parliament charged with safeguarding the federal electoral process.
Poilievre dismissively suggested that one of his detractors hadn't read the bill, much less his testimony at the Senate committee where he went after Mayrand.
That prompted a furious rejoinder from Liberal MP Wayne Easter.
"Dealing with this minister is like playing chess with a pigeon," he bellowed.
"He flaps his wings all over the place, knocks the pieces off the table, messes all over the table, then struts around like he won the game."
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