A federal judge on Monday blocked a Food and Drug Administration requirement that tobacco companies put big new graphic warning labels on cigarette packages by next September.

In a preliminary injunction, Judge Richard J. Leon of United States District Court in Washington ruled that cigarette makers were likely to win a free speech challenge against the proposed labels, which include staged photos of a corpse and of a man breathing smoke out of a tracheotomy hole in his neck.

The judge ruled that the labels were not factual and required the companies to use cigarette packages as billboards for what he described as the government’s “obvious anti-smoking agenda!”

The 29-page ruling was a setback for Congressional and F.D.A. efforts to bolster the warnings on tobacco packages. The agency has said they are the most significant change to health warnings in 25 years.