The justices of the U.S. Supreme Court may have to live with occasional demonstrators on the grounds of their courthouse, provided the protests don't relate to the court's business or interfere with its work, a federal appeals court said yesterday.

In a 2-to-1 decision, the U.S. Court of Appeals ruled that a federal statute that imposes an absolute ban on "expressive conduct" on the Supreme Court grounds, including picketing and leafleting, is unconstitutional. The government argued that the strict law was necessary to maintain the "dignity and decorum" of the Supreme Court. But the appeals court said that was not enough to justify a ban on free expression.

The decision came in the case of members of the Atlantic Life Community, a confederation of Christian activists, whose members were threatened with arrest for distributing leaflets and carrying a picket sign on the Supreme Court grounds. The leaflets described religious meetings involving Central America, and -- on another occasion -- removal of federal judges. The picket sign bore the words of the First Amendment. No arrests were made.

The Supreme Court itself has long held that the government may have some interest in limiting free expression in such public places as courthouses, when its exercise would interfere with normal operations. But the appeals court said it could find "no interest" to support absolute prohibition of such activity around the Supreme Court.

"Indeed, we believe that it would be tragic if the grounds of the Supreme Court, unquestionably the greatest protector of First Amendment rights, stood as an island of silence in which those rights could never be exercised in any form," Judge Harry T. Edwards wrote for the majority. He was joined in his opinion by Judge Ruth Bader Ginsburg.

The court noted that another federal statute prohibits demonstrations intended to influence a judge or interfere with the administration of justice.

Judge George MacKinnon, saying he objected to the majority's attempt to turn the Supreme Court grounds into a public forum, wrote that the statutes maintain the government's interest in order and decorum at the Supreme Court, and preserve the "appearance of justice." MacKinnon warned that "two lonely pickets today would lead to the hordes of tomorrow . . . . "