A survey conducted by a large Canadian polling firm shows a pattern of misleading phone calls during last May's federal election that appears to have targeted opposition supporters.

Ekos Research Associates says its survey found that Liberal, NDP and Green party supporters in seven key ridings were much more likely to report receiving a misleading telephone call in the final days of the election than Conservative supporters in the ridings.

The calls would appear to be from Elections Canada or the campaign office of a local candidate and would include erroneous information about changes in voting station locations.

The Ekos survey was commissioned by the Council of Canadians and performed in mid-April in the seven ridings where the advocacy group is now seeking new elections.

Garry Neil, the executive director of the Council of Canadians, says the research suggests the calls were effective in reducing voter turnout.

"With all the evidence we have now submitted, we believe we have a very strong court case to overturn the election result in the seven ridings where we are supporting legal actions," Neil said in a statement Tuesday.

He added: "The evidence is leading inexorably to one conclusion. Someone in a senior position in the Conservative Party with access to the central database and authority to spend money approved a widespread voter suppression campaign, that in our opinion affected the outcome of the last federal election in at least seven ridings."

The survey found that 16.9 per cent of eligible voters received calls related to polling stations. Of those, 22.3 per cent were told of polling station location changes. That amounts to 3.77 per cent of eligible voters. That's a significant number, Ekos says, because the margin of victory in the seven ridings in question ranged from 0.03 to 2.02 per cent.

While all party supporters were more likely than Conservatives to receive the calls in the ridings in question, Liberal supporters were three times more likely to receive a misleading call than Conservative supporters, the study found.

As well, voters in the ridings were 50 per cent more likely to have received robocalls than those in 106 other ridings used as a comparison.

"These results strongly suggest that significant voter-suppression activities took place that were targeted at non-Conservative voters," Ekos Research said in an affidavit filed as part of the Council of Canadians' legal challenge of the results in the seven ridings.

The pattern is "highly statistically significant and we can say with confidence that this is not an artifact of chance," Ekos president Frank Graves wrote.

The poll sampled 3,297 Canadians in the seven ridings, as well as a control group of 1,500 respondents in other ridings where there were no allegations of misleading calls. The survey was performed using an automated phone system, not with live poll workers.

Ekos says its results are accurate to within plus or minus 1.7 percentage points, 19 times out of 20.

Elections Canada is reviewing more than 700 official complaints of robocalls from people in every part of the country. Many said they received these calls after first getting a phone call to find out if they were voting Conservative.

The seven ridings Ekos surveyed were:

  • Yukon
  • Nipissing-Timiskaming in Ontario
  • Elmwood-Transcona in Manitoba
  • Saskatoon-Rosetown-Biggar
  • Winnipeg South Centre
  • Don Valley East in Toronto
  • Vancouver Island North

All were won by Conservative candidates by margins of less than 1.3 per cent, with the exception of the B.C. riding, in which the Conservative candidate won with a wider margin.

Graves said it's possible that some of those who responded to the survey were swayed by their own politics.

"I don't doubt there are some people in the sample who said things because they had an axe to grind one way or the other. But those (responses) would never explain the magnitude effects we're seeing here today," said Graves.

Trying to persuade someone not to vote, or stopping someone from voting, is illegal under the Elections Act.