Fox News will host a debate on gay marriage between Ted Olson and Tony Perkins.

Olson represented plaintiff couples in cases challenging restrictive marriage bans in California and Virginia. He won both those cases.

Perkins is the president of the Christian conservative Family Research Council (FRC).

“Both sides in the same-sex marriage debate are looking to the Supreme Court as it decides whether or not to weigh in on the issue,” Fox News said in a press release announcing the Fox News Sunday debate. “The High Court is set to discuss cases from Kentucky, Michigan, Ohio and Tennessee, and decide whether to rule on petitions challenging state bans on same-sex marriage. We'll debate what has become a key social issue within the country, exclusively with Ted Olson, former Solicitor General who served as Co-Counsel for the plaintiffs in Virginia's same-sex marriage case, and Tony Perkins, President of the Family Research Council.”

Writing at Equality Matters, Carlos Maza pointed out that FRC was labeled a hate group in 2010 and Perkins' appearances on cable news shows have plummeted since.

“Perkins' FRC was labeled a hate group by the Southern Poverty Law Center (SPLC) in 2010 because it has often promoted smears and falsehoods about the LGBT community,” he wrote. “Perkins' history of extreme anti-gay work is well documented: he's made a career of linking homosexuality to pedophilia and calling homosexuality a health risk.”

“The hate group leader has lost credibility on other cable news networks, but continues to receive warm welcomes on Fox. On Sunday, he'll have yet another chance to preach his hate-driven misinformation to a national audience.”

Olson and Perkins previously squared off on Fox New Sunday in October of 2014.

(Related: Tony Perkins: Supreme Court enabled “evil bidding” with gay marriage decision.)