Two of the three Democrats running in the special election to replace former U.S. Rep. Trent Franks are facing lawsuits challenging their right to appear on the ballot.

The suits allege that Brianna Westbrook and Gene Scharer are ineligible for the Democratic primary because many of their qualifying signatures are invalid.

The lawsuits were filed by Lynda Vescio, a supporter of the other Democrat in the race, Dr. Hiral Tipirneni. None of the 12 Republican candidates' signatures were challenged by Thursday's deadline.

Ballots have already been mailed to overseas military voters, making a successful court challenge problematic. The primary election is Feb. 27, followed by an April 24 general election.

Franks resigned from his seat in the heavily Republican district last month, amid sexual harassment allegations.