AUSTIN — A federal judge dismissed a civil rights lawsuit Friday by the conservative group Empower Texans, ruling that there wasn't a legitimate threat the group would be prosecuted.

The tea party group sued on Feb. 28 to prevent Attorney General Ken Paxton and the district attorneys of Travis, Tarrant and Midland counties from launching a criminal investigation into its use of a fictitious entity, the "Texas Ethics Disclosure Board," during the primary election season.

Representatives from Empower Texans said they plan to keep using the name and claimed the fear of prosecution "has had a chilling effect on [their] speech," a violation of the group's First Amendment rights.

The organization sent voters mailers that listed the lobbying clients of Fort Worth Rep. Charlie Geren's wife, Mindy Ellmer. One person in Tarrant County lodged a complaint with Travis County District Attorney Margaret Moore, claiming Empower Texans' use of "Texas Ethics Disclosure Board" on the mailers violated a law prohibiting people from impersonating government officials.

In his ruling, U.S. District Court Judge David Counts of Midland wrote that Empower Texans "does not demonstrate that ... a credible threat of prosecution exists."

Only one person suggested that the group's use of "Texas Ethics Disclosure Board" violated state law, which is not enough show that it did, Counts wrote.

The Travis County district attorney is reviewing the sole complaint filed against Empower Texans. The organization can only speculate about future prosecution, which does not warrant an injunction against potential investigations, Counts said.

Counts also denied Empower Texans' request for a temporary restraining order that would prevent the district attorneys of Travis, Tarrant and Midland counties from starting a criminal investigation.

Geren, a Republican, won his primary contest against Fort Worth businessman Bo French, who received thousands from Empower Texans and conservative backers who were trying to oust Geren and other moderate Republicans, many of whom were closely aligned with outgoing House Speaker Joe Straus.

Geren told The Dallas Morning News in February that he'd countered Empower Texans' move by buying as many internet domain names for the group as possible.