The Council of Canadians, chaired by Maude Barlow, is seeking to overturn election results in seven federal ridings, based on allegations of misleading calls during the 2011 election. (Canadian Press)

The legal challenge seeking to overturn last year's federal election result in seven ridings won by Conservatives will be heard in court in mid-December, the Council of Canadians said Wednesday.

The group is backing nine voters who say there is evidence of voter suppression and that the election result should be overturned in ridings where the result was close. They say a pattern of misleading calls, both live and automated robocalls, shows a co-ordinated effort to keep Canadians away from the polls on May 2, 2011.

The Council of Canadians said that a hearing of the evidence has been scheduled for Dec. 10 to 14.

However, the case will be in court before then, in September, because of ongoing arguments related to it.

The voters bringing the court challenge has asked for Elections Canada to provide details on complaints received from voters in the robocalls affair. Elections Canada says it received some 800 complaints from 200 federal ridings about misleading phone calls in the 2011 federal campaign. The agency has not provided the detailed information.

A lawyer for the Conservative party, Arthur Hamilton, says the demand for specific details would "interfere with the case timetable" and it is opposed by his clients.

The Federal Court has been asked to decide whether Elections Canada has to turn over the requested information. The decision is expected to be delivered on Sept. 18.

At that time the parties will also argue a motion from the lawyer acting for the seven Conservative MPs in the case that asks the challengers to put up $250,000 to cover the MPs' costs in case the challengers lose.

With files from CBC News