Prime Minister Stephen Harper brushed off accusations of electoral fraud in the Commons Monday and rejected opposition calls to hold by-elections in affected ridings.
Opposition parties have managed to knock the Conservative government off course in recent days with allegations that dirty tricks skewed races in the 2011 federal election by discouraging people from voting.
"Voters want the government to protect them against electoral fraud," NDP Leader Nycole Turmel said. "Is the Prime Minister prepared to force by-elections to restore voter trust?"
Mr. Harper challenged his political rivals to produce proof of Tory misbehaviour.
"The Conservative Party of Canada has denied such allegations," he said. "We don't have any such information. If the NDP has – and I am not sure that is the case – then the NDP must turn it over to Elections Canada."
The "robo-call" and voter-suppression scandal has overwhelmed political debate in Ottawa, leaving the Harper government fielding a flood of allegations that Conservative operatives used automated calls and live callers to discourage NDP and Liberal voters from casting ballots.
The Commissioner of Canada Elections, who enforces the Elections Act, has confirmed he is investigating complaints related to "crank calls designed to discourage voting, discourage voting for a particular party, or incorrectly advise electors of changed polling locations."
The Tories have denied engineering a voter suppression scheme but acknowledged at the same time that a rogue staffer might have done things without campaign consent.
They didn't identify any suspects but a Conservative staffer who worked on a campaign in Guelph, Ont., has since resigned from his current job working for a Mississauga MP.
The New Democrats and Liberals allege the problem goes beyond Guelph and have listed 29 ridings where they claim voters were either misled by automated calls purportedly from Elections Canada about where to cast ballots, or where live callers misrepresented themselves as working for rival parties. In some cases, voters allegedly received harassing late-night calls.
Interim Liberal Leader Bob Rae called on Mr. Harper to concede the allegations and cooperate with Elections Canada.
"When is the Prime Minster of Canada going to take some degree of personal responsibility for what has taken place?"
The prime minister challenged Mr. Rae to show proof, accusing the Liberals of making "broad sweeping allegations" without foundation.
The opposition contends the growing list of ridings across the country shows several people, not just one or two bad apples, were involved in a systematic, orchestrated effort to win tight races by misleading non-Conservative voters. This is a tactic, the opposition says, that has been imported from the rough-and-tumble culture of U.S. campaigning.