The next court date has been set for May 31 in former Tory staffer Michael Sona's Elections Act case related to robocalls made in Guelph during the 2011 federal election.

Neither Sona nor his lawyer were present in court Friday. Sona has yet to enter a plea on the charge but has maintained his innocence in interviews.

After nearly two years of Elections Canada investigations, the Director of Public Prosecutions laid a charge last month under section 491(3)d of the Elections Act, which prohibits preventing or trying to prevent a voter from casting a ballot.

The Crown can choose between charging Sona with an indictable, or more serious, offence, or a summary offence. The maximum penalty for the indictable offence is up to five years in prison and a $5,000 fine, while the maximum for the less serious charge is up to one year in prison and a $2,000 fine.

Sona, 24, was the director of communications for Conservative candidate Marty Burke in the Guelph riding where voters say they received misleading calls that sent them to the wrong polling station.

He remains the only person charged, despite reports and a Federal Court challenge over misleading robocalls made in other ridings across Canada.

Earlier this week, a report from Elections Canada found thousands of errors in paperwork at polling stations across Canada.

A "last-minute issue" delayed the introduction of a much-anticipated Elections Reform Act last month.