The U.S. Court of Appeals yesterday overturned a U.S. District Court ruling that allowed the Christian Knights of the Ku Klux Klan to march from the Washington Monument to the Capitol along Constitution Avenue, keeping the route of today's planned march in doubt.

The ruling, which remanded the case to the lower court, came less than 24 hours before about 50 Klan members were to begin their parade at 14th Street and Constitution Avenue NW. The Klan still holds a permit to march from Seventh Street NW to the Capitol, where they plan a rally.

Late yesterday, American Civil Liberties Union legal director Arthur Spitzer, who is representing the Klan, said U.S. District Judge Louis F. Oberdorfer planned to hold a hearing last night to address the concerns of the appellate court. Any decision by the judge favoring the Klan could again be appealed immediately by the city, continuing the on-again, off-again nature of the longer march.

City attorneys appealed the U.S. District Court ruling allowing the longer march, saying D.C. police are unable to protect the Klan over the longer route.

Klan leader Virgil Griffin said yesterday from his Mount Holly, N.C., home that he was awaiting the court's decision before bringing his busload of supporters on the eight-hour trip to Washington. If the court decisions continue to go against his choice for a longer route, he said he is prepared to make the march without a permit.

"I don't need a permit to walk that street by myself," he said. "I will wear my purple robe and I will make my walk. If the D.C. police can protect Martin Luther King and the communists, they had better be ready to protect me." The march is expected to begin about 1 p.m., and thousands of counter-demonstrators are expected.

Griffin complained that two D.C. police officers visited him twice yesterday at the garage where he works and have made repeated visits to his home. D.C. police also visited Griffin at his home before the Klan's first march on Labor Day weekend, and they escorted the Klan members to the city.

The latest legal decision follows an unusual and public argument between D.C. police and the U.S. Park Police over jointly staffing the march route.

An alternate route to the one that covered seven blocks of Constitution Avenue was a seven-block march along nearby Madison Drive on the Mall, which is under Park Police jurisdiction. Griffin asked for that route as an alternative to Constitution Avenue after D.C. police told him and his lawyer that they were reluctant to issue a permit for the 11 blocks.

The National Park Service delayed issuing the Klan a permit when it discovered that D.C. police were refusing to assist Park Police on the Mall route, as is routine. Park Police in turn said they could not protect the Klan on Madison Drive and began an appeal to other federal law enforcement agencies for help.

In the split decision yesterday, Judges Harry Edwards and A. Raymond Randolph agreed with the city that a four-block walk along Constitution Avenue is sufficient to guarantee the Klan's right to free speech. Chief Judge Patricia M. Wald disagreed.

Edwards's opinion said that the four-block permit "does not cause irreparable harm" to the Klan. He said the lower court failed to rule on several specific points, including the assumption that permit holders always are allowed to parade the full length of Constitution Avenue, that absent the threat of violence against the Klan, they would have been given the longer route, and that threats of violence never may be considered in the assessment of a permit application.

Randolph said the Klan could "make its point regardless whether its members march one mile or two. But the Klan's members will not be able to take a single step without police protection."

Wald, in a dissenting opinion, said the Klan should have the longer route because, in the words of Oberdorfer, the route between the Monument and the Capitol is a "traditional segment of the nation's premier public forum."