A Conservative staffer has resigned following reports that Elections Canada is investigating fake election day phone calls used to keep voters away from polls.

Michael Sona, who until Friday was a staffer in Conservative MP Eve Adams's office, also worked for Conservative candidate Marty Burke in Guelph, Ont.

Voters in that riding complained they were the target of automated robocalls claiming to be on behalf of Elections Canada that directed them to the wrong polling station. Telling voters to go to the wrong or non-existent polling stations is a voter suppression tactic and illegal under the Elections Act.

Opposition MPs let loose on the Conservative Party on Thursday after an Ottawa Citizen report linked a call centre used by some of their campaigns to the robocalls.

Sona offered his resignation and it was accepted, a source told CBC News.

In a statement Thursday, the Conservatives' 2011 national campaign manager hinted that whoever was behind the robocalls acted alone.

"The party was not involved with these calls and if anyone on a local campaign was involved they will not play a role in a future campaign," Jenni Byrne said in a statement.

There is no public evidence Sona was involved in the robocalls.

Calls traced to Racknine

Nine Conservative campaigns used the services of Racknine, the call centre whose services were used for the fraudulent calls. It's not unusual to use call centres for legitimate campaigning.

Ridings across the country reported fraudulent calls on May 2, 2011, redirecting voters to the wrong polling station.

The RCMP told CBC News on Thursday that Elections Canada is investigating the matter.

Sona made news before the election when he allegedly tried to grab a ballot box at the University of Guelph. He claimed the polling station was illegal. A statement released by Burke's campaign said nobody from their team touched a ballot or ballot box. Elections Canada allowed the ballots to be counted.

Sona graduated from the University of Guelph in 2010, according to a webpage showing his professional history. He worked for Conservative MP Rob Moore from June 2010 until March 2011 and from May to September 2011. He also worked for Canadian Heritage Minister James Moore for four months in 2009.

Liberals demand emergency debate

Liberal Leader Bob Rae announced Friday he's asking House Speaker Andrew Scheer for an emergency debate into voter suppression.

"In my opinion, this debate is necessary because denying someone the opportunity to vote is to deny them the most basic right that exists in our democracy," Rae says in his letter to Scheer.

"These reports undermine the reputation of Parliament and cast a shadow over the legitimacy of all parliamentary proceedings."