WASHINGTON, D.C. -- A government lawyer faced heavy questioning today from a federal judge who raised doubts that the Food and Drug Administration (FDA) has the authority to force tobacco companies to feature graphic images on their cigarette packs that show the health effects of smoking.

U.S. District Judge Richard Leon expressed his concerns during a two-hour hearing, during which he closely questioned Justice Department lawyer Mark Stern on whether the nine graphic images proposed by the FDA convey just the facts about the health risks of smoking or go beyond that into advocacy, according to the Associated Press. The distinction is critical in a case over free speech.

If Leon concludes the images amount to advocacy, the tobacco companies have a good shot of blocking this specific regulation. Leon said he hopes to issue a ruling by the end of October.

In August, several major tobacco companies filed suit against the FDA challenging the nine graphic cigarette warning labels the government approved in June. R.J. Reynolds Tobacco Co., Lorillard Inc., Commonwealth Brands Inc. and Liggett Group LLC contend that the warnings -- which must be depicted on all cigarette packs and advertising by September 2012 -- are an unconstitutional way of forcing tobacco manufacturers to disseminate the government's anti-smoking message.

The tobacco companies gained support late last week when two advertising groups, the Association of National Advertisers and the American Advertising Federation, filed briefs in the suit. The groups argued that the labels infringe on commercial free speech and could lead to further government intrusion if left unchallenged.

However, in response to the suit, the FDA said the public interest in conveying the dangers of smoking outweighs the companies' free speech rights. The FDA also pointed out that Congress gave it the authority to require the new labels because existing warnings dating to 1984 were going unnoticed and health warnings weren't being conveyed effectively.

In court earlier today, lawyers for the tobacco companies argued that the government is free to tell people how to live through steps such as enacting smoking bans on teenagers and by requiring written, factual warnings on the sides of cigarette packages from the surgeon general about the effects of smoking, the news outlet reported. However, the government cannot "conscript" the companies "into an anti-smoking brigade," First Amendment lawyer Floyd Abrams told the judge.

Leon questioned Stern about why the images did not amount to advocacy, asking what is the line between advocacy and fact.

"This is not an ordinary product" and the images coupled with written warnings are designed to communicate the dangers to the public, including youngsters as well as adults, Stern replied.