Most opponents of the proposed Fair Elections Act say there is no evidence that voter fraud at the polls ever happens in Canada.

Marc Mayrand, Chief Electoral Officer of Elections Canada, told a parliamentary committee in early March his agency has conducted investigations into reports of voter fraud. But he said no evidence of voter fraud at a "systemic or organized" level has been found.

Even so, the government believes voter fraud does exist. Its new electoral reform act seeks to eliminate the practice of vouching, and one of the reasons given is that vouching is vulnerable to abuse.

Vouching occurs when a qualified voter attests for another voter who lacks proper identification or proof of address but lives in the same polling division.

Critics, including Mayrand, say getting rid of vouching could potentially disenfranchise 120,000 people, especially seniors, students, the homeless and people living on remote reserves.

"We should not have a society where underrepresented or marginalized people are pushed out of the electoral process," Yasmin Dawood said in a phone interview from the University of Toronto.

Dawood is one of over 150 professors across the country who sent a letter to Prime Minister Stephen Harper and all MPs about concerns over the removal of vouching and other aspects of the Fair Elections Act.

Eliminating vouching, Dawood said, "raises the question mark around voter suppression, and that is a much more serious problem than that you might have fraudulent voting."

Voter fraud almost impossible to prove

Stephen Thiele, a Toronto lawyer, says voter fraud is almost impossible to prove.

Thiele represented former Liberal MP Borys Wrzesnewskyj in his ultimately unsuccessful attempt to have the 2011 election in his riding overturned because of numerous voting procedural errors.

"Unless a scrutineer sees some kind of action take place in a polling station or somebody witnesses someone saying, 'Hey, I'll give you 10 bucks if you vouch for somebody,' proving a fraud is going to be difficult," Thiele said.

In the past, Thiele said, vouching was seen as an opportunity for voter fraud.

"In 2007, [the government] got rid of multiple vouching and serial vouching because of the concerns that they were being used by shady characters in elections for fraudulent purposes," he said.

After 2007, new rules stipulated a person can vouch for only one voter. As well, one vouched-for voter can no longer vouch for others.

In the Toronto riding of Etobicoke Centre, which Wrzesnewskyj lost by only 26 votes to Conservative MP Ted Opitz, Thiele says there were multiple vouching errors. He cited the example of one poll where six people were vouched for, but there was no record of either the voucher or the vouchee.

"How do I prove a fraud at that point when I don't even know who the people were?" Thiele said.

The high rate of procedural errors uncovered in just one riding by the Wrzesnewskyj case prompted Elections Canada to commission a report from retired Elections B.C. chief Harry Neufeld.

Neufeld found a 25 per cent rate of error in the vouching process in his survey of the 2011 federal election. The errors, Neufeld said, were serious enough to warrant the overturning of an election result.

He recommended Elections Canada make an effort to reduce the need for vouching. The government's response was to get rid of it altogether.

The robocalls case is voter fraud

Evidence that voter fraud does exist is borne out of the robocalls scandal in Guelph, Ont. In an ongoing Elections Canada investigation, one person has been charged with commissioning calls that directed voters to the wrong poll on election day in 2011.

Steven Shrybman, an Ottawa lawyer who worked on a court challenge involving six other ridings that were besieged by similar misleading robocalls, said the judge in his case didn't find the vote was affected by the calls. Federal Court Judge Richard Mosley did, however, find that fraud had occurred.

Asked if a cadre of partisan voters could be the tool for voter fraud instead of phone calls, Shrybman said he believes individual voter fraud happens only "in the margins ... It's trotted out as the justification of all kinds of voter suppression."

But voter fraud could be a factor in a very close election, he said. The political party trying to influence the vote would need to know the riding intimately.

"They would know ... which polls mattered and who mattered in those polls and how [people] were going to vote or not vote. They would target a key poll or two, say with an older demographic, with a particular tactic," Shrybman said.

Thiele said there has to be a balance between the right to vote and the integrity of the voting system.

"You have to balance the fact that in order for democracy to work well, people have to have confidence that the process has a high level of integrity in it."