Rejecting the possibility that a single Conservative party staffer was behind automated phone calls placed on election day 2011, opposition MPs insist the "robocalls" were part of a deliberate, planned strategy to mislead Liberal and NDP voters.

"The real issue is that there was a systematic effort to undermine our democratic system by lying to people about where to go on election day," New Democrat MP Pat Martin told CTV's Question Period.

During a heated exchange among Conservative MP Dean Del Mastro and Liberal MP Frank Valeriote, Martin suggested the calls were part of well-planned Tory strategy to send unsuspecting voters astray on election day.

"The really important thing is that 34 ridings -- that we know of and the number are growing everyday -- received these terrible phone calls advising people that their voting station had changed," Martin said. "And they go trundling down to this phony voting station -- some may never come back."

Del Mastro said the Conservatives are just as concerned as opposition MPs about the widening "robocall" scandal. In fact, he said voters in his Peterborough riding have been bombarded with automated calls too.

"The NDP has been robocalling my riding for a month about OAS (Old Age Security)," Del Mastro said.

But Martin and Valeriote said the issue is far more serious than nuisance calls. If the messages contain misleading information -- as has been alleged -- then the issue is a police matter, they said.

The opposition MPs said the automated phone call allegations fit a disturbing pattern. Tory campaigners placed many nuisance and crank calls during the 2011 election campaign, they alleged, saying the tactics were imported from the U.S.

"You can't overstate how serious that is," Martin said. "The most fundamental freedom we enjoy as citizens in a democracy is the right to vote in a federal election, free and fair, and without interference or without molestation of any kind.

"A lot of good people will lay down their lives to fight for that freedom, so let's not make this a joking matter."

The automated call scandal enveloped the capital after an Ottawa newspaper revealed that an Edmonton-based call centre with Tory ties placed calls on election day in Guelph, apparently aimed at suppressing the Liberal and NDP vote.

The calls were traced to Racknine Inc., of Edmonton, which worked for the Conservative Party's national campaign, as well as at least nine other Conservative candidates including the prime minister.

Some reports linked a 23-year-old Tory staffer, Michael Sona, to the calls made in Guelph, Ont. Although there is no evidence Sona was behind the calls, he resigned from the office of Toronto-area MP Eve Adams last week.

But Valeriote said the scandal goes deeper than a young Tory aide.

The automated calls may have been placed in as many as 34 ridings, he noted, suggesting it was the work of a sophisticated operation -- not one young, misguided individual. The Liberal MP suggested the Conservatives have been compiling lists of Liberal and NDP voters for years.

"He would have had to have access to voter lists, lists that identified Liberal and NDP supporters, and I can tell you . . . . that the Conservatives have those lists," Valeriote said

"They have spent years calling people, asking them to identify what party they support. They created these kind of lists." Now, they're using them to identity Liberal and NDP supporters "so that they can create this kind of absolute chaos on election day."