The Democratic frontrunner to challenge Rep. Rick Renzi (R-Ariz.) has filed a libel lawsuit and is seeking a restraining order against her husband’s ex-wife in Canada over comments the ex-wife posted on a primary opponent’s blog last month.

Republicans have tried to make a campaign issue of the nasty child support battle that took place between candidate Ellen Simon’s husband, Blaine Tanner, and his ex-wife, Pamela Tanner.

The issue has not gained much traction in the local media, despite a press release issued by the Arizona Republican Party. Pamela Tanner took matters into her own hands on July 4 by posting on the website Arizona Congress Watch and the blog of Simon’s Democratic primary opponent, Mike Caccioppoli.

Simon and Blaine Tanner responded by suing her in Canadian court for libel for the comments on Caccioppoli’s website and seeking an injunction that would prevent her from repeating them. In the suit, which was served over the weekend, Simon and her husband allege that Pamela Tanner has attempted to extort $10 million from them by threatening media exposure.

Pamela Tanner’s postings criticize Simon for allegedly not being involved with one of her stepchildren, and she claims to have damning evidence against Blaine Tanner that proves he has lied in past financial statements. She said he has breached a court order three times since their child-support dispute was resolved in the courts in 2000.

Pamela Tanner posted her allegations twice on Arizona Congress Watch and once on Caccioppoli’s blog on July 4.

The Tanners’s child support battle has been chronicled in Canadian and American newspapers, including an extensive article in 2000 in the Toronto Star, Canada’s largest paper, which labeled Blaine Tanner one of Ontario province’s worst deadbeat dads. The article said Tanner was hundreds of thousands of dollars in arrears.

Blaine Tanner was married to Simon and living with her in Ohio at the time.

Simon’s campaign said the dispute was simply a long, drawn-out battle that got resolved shortly after the articles came out, and that many accusations that have appeared in the media are untrue. In an interview with The Hill last month, Simon said it was a domestic matter in Canada that “has nothing to do with me” or her campaign, and she called Pamela Tanner “vindictive” and “crazy.”

Simon, a prominent civil rights attorney, said at the time that she had been in talks about launching a lawsuit.

The suit, filed with Ontario’s Superior Court of Justice in Ottawa, alleges that Pamela Tanner has “engaged in an unremitting and malicious campaign against” Blaine Tanner and that she began targeting Simon once she learned of her candidacy.

“This has been a pattern of conduct of hers for years,” Simon said Tuesday. “It’s improper, illegal, inappropriate and harmful. That’s why we have laws.”

Pamela Tanner said she “just wanted people to know the truth. I didn’t write anything maliciously.” She said she plans on filing some sort of counter-claim in Arizona.

The lawsuit says 14 of Pamela Tanner’s statements in the blog posting are false and defamatory, including a statement claiming that Blaine Tanner has breached the court order. An affidavit filed by Simon says she has been involved with all of her stepchildren except one, who she said is predisposed against her because of Pamela Tanner’s efforts.

Simon and Blaine Tanner are seeking $250,000 and $100,000, respectively, in libel damages and $100,000 combined in aggravated, punitive and exemplary damages. They also say Pamela Tanner attempted to extort $10 million from them by leaving a voicemail threatening to go to the media in April when Simon was weighing her candidacy.

Citing the pending case, Simon on Tuesday declined to comment on whether she and her husband have the voicemail recording, and if so, whether they plan to use it in court.

The Arizona Republican Party in late June sent out a release citing the Star article that charged Simon with being a candidate of “questionable character.” State and national party officials and Renzi’s campaign say that Blaine Tanner’s past speaks to Simon’s character, and a national Republican operative said last month that the party was “fully prepared to make” Simon’s husband an issue in the campaign.

Simon’s campaign said bringing up Blaine Tanner’s past is meant to distract from Renzi’s dismal record and the real issues in the campaign.

National Republican Congressional Committee spokesman Jonathan Collegio argued that Simon is attempting to cover up her character issues by gagging her detractors. Arizona Republican Party spokesman Garrick Taylor said “it’s ironic” that Simon, who has done work on behalf of the American Civil Liberties Union, would launch a lawsuit to restrict Pamela Tanner’s speech instead of refuting her claims.

Simon has raised more than half a million dollars through the second quarter, including $275,000 of her own money, and is the favorite in the Sept. 12 primary, in which none of her opponents has more than $10,000. Simon recently began airing television ads.

Renzi is a second-termer who won reelection by a surprising 59-36 margin in 2004 in the 1st District. The seat is supposed to be the most competitive in the state, but the leading Democrat, former state lawmaker Jack Jackson Jr., dropped out in March, citing a lack of help from the national Democratic Party.

Simon announced her candidacy in May.

Jim Pederson, the former Arizona Democratic Party chairman who is currently running against Sen. Jon Kyl (R-Ariz.), recently praised Renzi’s work in Congress, noting that the Republican has done a “pretty good job” and that it will be tough to beat him.

Simon’s campaign claims Renzi is vulnerable and points out that he has been named one of the 13 most corrupt members of Congress by Citizens for Responsibility and Ethics in Washington.