The chief of the U.S. Park Police said a permit will not be issued for a Klan group to march Sunday on the Mall unless the military, the D.C. National Guard or U.S. Marshals Service sends reinforcements to help keep order.

Chief Lynn Herring said he has taken the unusual step of asking for federal support because D.C. police are refusing to provide routine assistance. Both police agencies have said they are concerned about the potential for a violent confrontation between the Klan and demonstrators who have vowed to stop the march.

"This is the first time we have not had the support of D.C. police," Herring said. "If we cannot supply the security to protect persons and property, we cannot grant the permit."

If the permit is not granted, Klan leader Virgil Griffin and Arthur Spitzer, the legal director of the local chapter of the American Civil Liberties Union, have said they will go to court and argue that the Klan's First Amendment right to free speech has been violated.

"We find it dismaying that D.C. police are shirking their responsibility here to protect the First Amendment {rights} of an unpopular group," Spitzer said. "To our knowledge, there has never been a previous occasion where one local police force has refused a request for help from another."

Neither D.C. Police Chief Isaac Fulwood Jr. nor his spokesman could be reached for comment yesterday.

At the behest of the city police, the Klan last week agreed to change its march route so members would walk through District and U.S. Park Police jurisdictions. They asked to march along the Mall between 14th and Seventh streets NW on Park Police territory and then onto four blocks of Constitution Avenue in the jurisdiction of D.C. police.

Herring had expected D.C. police to help keep order along the Mall portion of the route. Police agencies within the District usually assist each other because demonstrations, festivals and criminal investigations often cross jurisdictional lines.

Herring said he has 500 officers to call on for the march, a number he said is not enough to maintain order. That is why he asked for federal help when it became clear he would not receive help from the 4,600-member D.C. police department.

Yesterday, a spokesman for the White House said the military could not be used as law enforcement officers. A spokesman for the U.S. Marshals Service said the service had not received a formal request for help and it would be up to the attorney general to make the decision.

Erneido Oliva, deputy director of the D.C. National Guard, said the policy of the Guard is not to have direct contact with any demonstrators. However, the Guard can help control traffic.

During negotiations with the Klan over an earlier application for permission to march along 11 blocks of Constitution Avenue, D.C. police said they were concerned about the cost of protecting the Klan from counterdemonstrators and about providing police services for the city during the parade. Last night, Fulwood notified Spitzer that he would not let the Klan march the longer route on city streets. But the D.C. police chief did approve a new permit that covers four blocks on Constitution Avenue.

Spitzer said D.C. police had been reluctant to allow the Klan to march in Washington at all. He said he will ask a judge to order the D.C. police to allow the Klan to march the longer route on Constitution Avenue or to help the Park Police protect the Klan march along the Mall.

About 40 Klan members attempted to march in Washington on Labor Day weekend but were discouraged from doing so by D.C. police when several thousand anti-Klan demonstrators massed along Constitution Avenue, blocking the street and injuring four officers. The Klan members were bused from the Pentagon parking lot to the Capitol, where they held a brief rally.

A few days after the rally, Griffin said he thought his group's constitutional rights had been violated and said they would apply for another permit.

Last week he said it was important for them to march in Washington because they had encountered resistance in other cities. "They keep saying if Washington can keep you from marching, we don't have to let you march either," he said.

Capitol Police have granted a permit for the Klan to hold a rally on the plaza on the west side of the Capitol.