A coalition of influential political conservatives sent a letter of complaint to companies that advertise on the CBS news program Face the Nation hosted by Bob Schieffer.

The letter, organized by the American Family Association, asks companies to avoid advertising on Face the Nation because of derogatory remarks made by Shieffer when he interviewed Tony Perkins of the Family Research Council the Sunday before oral arguments on gay marriage in the Supreme Court.

Shieffer introduced Perkins on the April 26th program by telling him there was a concerted effort to keep him off the broadcast because he “did not represent all Christians” and because FRC is a “hate group,” according to the Southern Poverty Law Center.

At the time, Perkins ignored Shieffer’s derogatory comments, and the anchor did not bring them up again. But, according to the group letter sent to CBS advertisers, the damage had been done. The letter calls the Shieffer comments “an ambush” that implied “Mr. Perkins is an anti-gay bigot…”

“This was insulting and disgracefully dishonest on many levels,” says the letter.

A letter from a number of conservative leaders was sent to CBS News right after the April 26 incident. Brent Bozell told Breitbart News, “How hard is it to apologize, especially if his anti- Christian slur was accidental? Unless, of course, it was intentional. What else should we conclude?” CBS ignored the letter.

The new letter to advertisers — signed by Brent Bozell (Media Research Center), Tom Benton (American College of Pediatricians), Brian Brown (National Organization for Marriage), Tom Fitton (Judicial Watch), Frank Gaffney (Center for Security Policy) and other notable conservative leaders, accuses CBS of behaving “callously and dishonestly.”

Of particular concern is the reliance by Schieffer on the Southern Poverty Law Center, the group that labels FRC and other Christian opponents to gay marriage as “hate groups” on par with Nazis.

It was the inclusion of FRC in the Southern Poverty Law Center hate list that motivated an armed SPLC supporter to invade FRC’s headquarters in Washington D.C. with the intent of killing as many employees as possible. He was stopped but only after wounding a security guard who subdued him.

The letter says SPLC is now largely discredited and has even been criticized by liberal groups for inflating its list of hate groups for the purposes of fundraising. According to the letter, “Within the past year, the FBI, Defense Department, and the U.S. Army have distanced themselves from SPLC materials.”

The letter says FRC could hardly be a fringe hate group since: “It counts Senators, U.S. House members, governors, state legislators, judges, prominent corporate leaders, leading clergy, artists, musicians, and academics among its friends and supporters.”

The group asks advertisers not to support “behavior along the lines displayed by Mr. Shieffer towards Tony Perkins. It is not open season on Christians in America. Please let them know it.”