Loudoun County Supervisor Eugene Delgaudio, who for years has publicly decried what he refers to as a “radical homosexual agenda” in the United States, announced this week that he will fight back against his nonprofit organization’s designation as a hate group by the Southern Poverty Law Center.

Delgaudio’s attorney, Charles King, said on Monday that he had submitted a subpoena request for records held by the SPLC, a prominent civil-rights organization that in 2012 included Delgaudio’s nonprofit, Public Advocate of the United States, on a list of hate groups in the United States.

The organization, led by Delgaudio (R-Sterling) since 1981, has a long history of controversial mass mailings, publications and street theater performances targeting gay rights, frequently prompting national headlines and widespread criticism from civil-rights groups and Delgaudio’s political adversaries. In 2012, the SPLC filed a lawsuit against Public Advocate on behalf of a same-sex couple whose engagement photo was allegedly stolen from their wedding blog and distributed on anti-gay-rights campaign mailers in Colorado. The case remains active.

In a statement Monday, King said that “almost every article written about Supervisor Delgaudio mentions the designation of Public Advocate as a hate group by the Southern Poverty Law Center.”

The subpoena would seek detailed information about the criteria, research and decision process that was used to issue that designation, according to King’s Feb. 28 request submitted to Loudoun County Circuit Court Clerk Gary Clemens.

“The quality of the SPLC’s work goes to the weight to be accorded the hate group designation,” King said. “Was the SPLC’s decision to name Public Advocate a hate group made reluctantly, after careful study, or did some intern decide to send out a press release? This is an important question.”

King said the subpoena would be served on the Alabama-based organization this week.

Heidi Beirich, director of the SPLC’s Intelligence Project, said Tuesday that she could not comment on the subpoena as it had not yet been received. But the organization would not recant its designation, she said.

“We stand by, absolutely, our characterization of Public Advocate as an anti-LGBT hate group,” she said. “The kinds of statements Delgaudio has made have been absolutely outrageous and ugly… that is something that we are not going to change our mind about.”

Delgaudio, a four-term supervisor, is also defending himself against a recall petition filed by Sterling voters who are aiming to remove him from his seat on the county Board of Supervisors, citing allegations that he used his public office to benefit his political campaign. That case is pending in Loudoun County Circuit Court, with an upcoming hearing scheduled for March 25.