Should the Christmas Pageant of Peace, replete with grazing reindeer and the sparkling national Christmas tree, have sole claim to the Ellipse for the last three weeks of December every year?

A group called the Christian Service Corps, which wants to produce a drama about Nativity, does not think so and has sued the National Park Service to gain access to the Elliptical acreage immediately south of the White House.

In a spirited debate on the issue yesterday before U.S. District Court Judge William B. Bryant, corps lawyer Jerry A. Moore III declared that "we're entitled as any other group . . . to go on the oval area. The burden is on the government to show some compelling reason for their restriction."

The park service has told the corps, a Washington group which trains missionaries for service in 42 countries, that it can use land just off the Ellipse for the drama it wants to present starting Monday and continuing through Christmas Eve.

But the park service has maintained that the Pageant of Peace, which the park service cosponsors with city business, religious and civic groups, should have the sole right to the Ellipse in the latter part of each December even though it only uses one-fourth of the land.

"You're saying that no one can do anything on the other three-fourths?" an incredulous Bryant asked Assistant U.S. Attorney Craig Lawrence. "Thats utterly ridiculous. You're saying that everybody's been treated equally in that they all have been denied permission" to use the Ellipse?

"That's correct," Lawrence replied.

"For you to reserve one-fourth of it and not allow use of the rest of it . . . thats on it's face is clearly unreasonable," Bryant said.

Moore contended that to forbid the corps from using the Ellipse denies a First Amendment right to free speech on public ground. He also said that the trees just off the Ellipse make it difficult to produce a drama there.

"We're not imposing censorship here," Lawrence argued. "We're being evenhanded." He said other groups, including the American Nazis, also have been told they cannot use the Ellipse during the Pageant.

Barbara Berschler, an Interior Department lawyer, told Bryant that one reason to keep the other groups off the Ellipse during late December is to make clear that the government is not sponsoring any religiously oriented Christmas program. The government was barred in 1973 by the U.S. Court of Appelas here from having a federally sponsored Nativity scene as part of the Pageant of Peace.

Bryant said he would issue a ruling Monday on the dispute.