TORONTO - Ontario's highest court has upheld the sentence imposed on a former Conservative staffer convicted in the 2011 federal election robocalls scandal.

Michael Sona had asked Ontario's Court of Appeal to impose a shorter sentence than the nine months in jail he received in November 2014.

At the same time, Crown prosecutors asked the court to send Sona to jail for 20 months, arguing his earlier sentence wasn't harsh enough given the seriousness of his crime.

The appeal court dismissed both Sona's and the Crown's appeals, saying the judge who issued Sona's sentence properly took into account the man's prospects for rehabilitation and individual circumstances, as well as the need to protect democratic institutions and processes from attack.

Sona, who is now 26, was the first person convicted of wilfully preventing or endeavouring to prevent an elector from voting under the Canada Elections Act.

The trial judge said he believed Sona did not act alone in a scheme in which some 6,700 automated phone calls were placed on the morning of the 2011 federal election, largely to numbers in Guelph, Ont., wrongly telling people their polling station had been moved to a different location.