The Council of Canadians is backing applications asking the court to review the May 2011 election results in seven ridings where Conservative MPs narrowly won their seats.
The council alleges misleading or harassing phone calls in those ridings kept some people from voting and may have affected the outcomes.
But Conservative party lawyer Arthur Hamilton told the court Monday the legal applications to overturn the results, by law, should have been filed within 30 days of the election outcome being certified. That would have been by early June of last year.
Hamilton argued that since the applications were only filed in March, it is far too late for the court to consider them.
"These applications simply cannot be allowed to leave the starting gate," Hamilton told the court.
He argued that allowing the cases to be heard could cause a "free-for-all," setting a precedent in which anyone could challenge the results of an election at any time, meaning MPs would always be looking over their shoulders, never certain when their election win might be called into question.
But Garry Neil of the Council of Canadians said the clock starts ticking on the 30-day window when someone first realizes the fraudulent calls could have affected the outcome of the election.
"They didn't suspect that it affected the outcome of the election until it became public knowledge that this was a very, very widespread campaign," he told reporters outside the court.
In court documents filed earlier this year, the Conservatives claimed the council is more concerned with attacking them and raising money than getting to the bottom of the so-called robocalls affair.
Party lawyers called the council's conduct improper, unseemly and a clear abuse of the court's process.
The seven Conservative MPs targeted in the council's court action have asked the court to toss out requests to review the results in their ridings.
The council has countered that the Conservatives are attempting to delay the cases and drive up legal costs.
The law lets voters legally challenge the results in their ridings. If a judge finds anything that would have changed the outcome, a new byelection can be ordered.
Such decisions are extremely rare. But this spring, an Ontario judge ruled that enough suspect votes were cast due to clerical errors to warrant overturning last year's election result in a Toronto riding, where Conservative MP Ted Opitz beat Liberal Borys Wrzesnewskyj by a mere 26 votes.
If the decision stands, a byelection will have to be called in Etobicoke Centre.
The Supreme Court of Canada has agreed to hear Opitz's appeal of the ruling in early July.
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