U.S. District Judge Richard L. Williams said yesterday that "at the slightest suggestion" that the Alexandria and Arlington County police departments were beginning to enforce a new state ban on the display of sexually explicit books or recordings, he will issue an injunction preventing them from doing so.

Williams took this compromise stance after he was informed by attorneys for police chiefs in both jurisdictions that they don't plan to enforce the law until a court challenge to the new law's constitutionality is resolved.

A coalition of booksellers, publishers and bookstore owners as well as two Alexandria residents have challenged the the new state ban on the display of sexually explicit material that, even if not obscene, could be "harmful to juveniles."

The plaintiffs, who had asked Williams for a temporary order restraining the enforcment of the new law, say it will force them to remove best-sellers by authors such as Sidney Sheldon and Judith Kranz and the teen novels by Judy Blume from their shelves.

They have said that they have "no commercially viable means" of complying with the law and have asked that it be declared unconstitutional because the ban on display deprives adults and minors of access to sexually oriented though not obscene literature that is protected by the First Amendment.

Williams denied motions from the police chiefs' attorneys to dismiss the suit. He said it would be appropriate for the Virginia attorney general to defend the new law and he continued the case until representatives of that office could be present. Meanwhile, he said the law should not be enforced.

Alexandria deputy city attorney Robert L. Murphy, representing Public Safety Director Charles T. Strobel, said that "there will be no arrests in the interim."

Arlington assistant county attorney Ara Tramblian said Arlington Police Chief William K. Stover believes "there are ways the law can be applied in a constitutional way."

"In the meantime he has a grenade in his hand with the pin pulled," Williams said. "What if some member of the Moral Majority should bring a motion for him to enforce the law?"

Williams took their pledges and told attorneys for the plaintiffs that "at the slightest suggestion they are enforcing this thing, you just let me know and I'll issue an injuction."