RICHMOND, Va. -- Tobacco companies are gathering support in their legal battle against the Food and Drug Administration (FDA) over new graphic cigarette warning labels. In their corner now are two advertising industry groups which joined the opposition to the new mandates on Friday.

The Association of National Advertisers and the American Advertising Federation filed briefs with the U.S. District Court in Washington, D.C. in connection with the lawsuit brought by R.J. Reynolds Tobacco Co., Lorillard Tobacco Co., Commonwealth Brands Inc. and Liggett Group LLC. The advertising groups contend the labels infringe on commercial free speech and could lead to further government intrusion if left unchallenged, according to the Associated Press.

A hearing on a preliminary injunction to stop the labels, set to appear on packs next year, is set for Sept. 21, with a decision to come as soon as October.

"The new cigarette warnings are expressly designed to be propagandistic rather than informative," wrote the groups who represent hundreds of U.S. companies and thousands of advertising professionals. "If the government can deputize tobacco companies through their product packaging and advertisements to deliver its message, there is no reason it could not do so for other things -- and history shows it will not hesitate to do so."

For its part, the FDA said that the public interest in conveying the dangers of smoking outweighs the companies' free speech rights. The agency also said the financial costs to the companies of switching to incorporate the new graphics equals about one-tenth of their annual net sales, which the FDA said is not sufficient to justify the injunction, as CSNews Online reported last week.

The legal debate centers around the nine graphic cigarette warnings the FDA approved in June. The warnings are required to appear on all cigarette packs and advertising by September 2012.