The U.S. government's effort to put graphic warning labels on cigarette packaging hit a snag Wednesday when a federal judge ruled that the regulations violate free-speech rights protected by the Constitution.

The mandate is being pushed by the Food and Drug Administration in order to give the American public a stark warning about the  health dangers of smoking.

U.S. District Judge Richard Leon in Washington, D.C., found the policy unconstitutional because the images were neither designed to protect the consumer from confusion or deception, nor to increase consumer awareness of the risk; rather, they were crafted to evoke a strong emotional response calculated to provoke the viewer to quit or never start smoking.

Leon granted a preliminary injunction last November that blocked the new label requirement from taking effect in 2012. President Barack Obama's administration has appealed that decision to the U.S. Court of Appeals for the District of Columbia Circuit.

The administration is also expected to appeal Wednesday's ruling.

The warning labels, which were unveiled last year, include a slew of disturbing, provocative images designed to cover a range of cigarette packaging. The images include a depiction of the corpse of a longtime smoker; black, diseased lungs; and a close-up of smoking-damaged teeth and gums.

Tobacco companies have argued that the images are a manifestation of the government's anti-smoking agenda that go beyond simply increasing consumer awareness of the product's health risks.

Leon, who sided with cigarette makers on that front, argued that while educating the public about the dangers of smoking might be compelling, an interest in simply advocating that the public not purchase a legal product is not, he wrote in his 19-page ruling.

In addition, Leon argued the government can employ other strategies to deter smoking, such as raising cigarette taxes, or including a factual warning of its risk -- rather than the images -- on labels.

Cigarette packs already carry text warnings from the U.S. Surgeon General.

The FDA received regulatory authority over tobacco products under the Family Smoking Prevention and Tobacco Control Act of 2009. Under that law, the agency devised the policy in question, which requires cigarette makers to cover the top half of the front and back of cigarette packs with the gruesome warning labels. The regulation also says the images must be used in 20 percent of those companies' advertising.

In a statement issued after Leon's ruling, the Department of Health and Human Services said the decision will not impede its efforts to enforce stronger warnings on cigarette labels.

This public health initiative will be an effective tool in our efforts to stop teenagers from starting in the first place and taking up this deadly habit. We are confident that efforts to stop these important warnings from going forward will ultimately fail, the agency wrote.