A lawyer for seven Conservative MPs whose 2011 election wins are being challenged in Federal Court wants to see a $250,000 deposit on costs in case the challengers lose.

Nine Canadians in seven ridings have mounted the court challenge, backed by the Council of Canadians, a regular foe of the Conservative government.

In an email sent to supporters, Council of Canadians chair Maude Barlow says lawyers for the seven Conservative MPs have asked the challengers to put up $250,000 to cover the MPs' costs in case the challengers lose.

The Council of Canadians is backing nine voters who say there is evidence of voter suppression in the last federal election 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 news comes out of a case conference Wednesday during which the parties also discussed a request by the applicants for Elections Canada to release more information about its investigation into the calls. The election agency refused to provide the information and asked the court to decide whether it should be handed over.

"While these relentless obstructions by the Conservative Party continue to drive up legal costs, they will not dampen our resolve to defend democracy and restore voters' rights," Barlow said in the email.

The motion will be heard in Federal Court on Sept. 18, Barlow said. The court is also expected to decide that day whether Elections Canada should provide the additional information requested by Steven Shrybman, the lawyer for the applicants.

Defence costs 'significant'

A court document filed by one of the respondents and provided to CBC News by the Council of Canadians notes that the applicants put up $1,000 per application, but the court has the discretion to increase the security.

The respondents "must defend against the application and the costs of doing so will be significant," says the document, filed on behalf of Conservative MP Lawrence Toet.

The Council of Canadians has confirmed it is paying for the court challenge and in fact sought out volunteers for the court case, Toet says in the document, noting the organization has used the case as a fund-raising opportunity.

"These fundraising efforts have been successful with the Council reporting that they had raised $129,000 by mid-July, 2012. While trumpeting their successful fundraising, the Council have also been vocal about the fact that $129,000 is not nearly enough to support seven election challenges. The Council has indicated that fees and expenses for the court challenges were expected to reach $240,000 by the end of June," the document says.

A motion filed by Conservative MP Jay Aspin says the applicant in his case should have to put up $40,000 before the case is decided.

The applicants have already won a small victory in court when it ruled the case could go ahead despite a motion to dismiss filed by the Conservative MPs. The Conservatives said the case was filed too late, didn't back up the claims of the applicants and had no chance of success. The applicants responded that they brought the case as soon as they became aware of the possibility of a co-ordinated approach to the misleading phone calls.

This isn't the first court case as a result of the 2011 election. Voters in Etobicoke Centre are waiting for the Supreme Court to decide whether they should go back to the polls after an Ontario Superior Court justice found in favour of former Liberal MP Borys Wrzesnewskyj, who challenged Conservative MP Ted Opitz's win because some polling stations were missing the paper work they needed to prove those who voted were qualified to do so.