The Supreme Court's most-watched case of the year will be argued March 24, when a California father tries to convince the justices that the regular morning public school salute to the American flag is unconstitutional because of the reference to God.

Justices scheduled the one-hour argument on Monday, and also agreed to accept written arguments from other people and groups, including the mother of the girl in the case.

Michael Newdow (search), a doctor and lawyer, will argue the case himself, facing off with attorneys from a California school and possibly the Bush administration. The atheist from Sacramento, Calif., filed the case on behalf of his 9-year-old daughter.

Unsettled is whether the girl, who is not named in court records, will be allowed to attend the court's session.

She watched her father argue the case at the 9th U.S. Circuit Court of Appeals (search) in San Francisco, and Newdow has asked Supreme Court staff for information about security at the high court building. A California family court judge would assess whether he thinks the girl should make the trip.

The girl lives with her mother a majority of the time, and custody arrangements between Newdow and the mother have been hard-fought.

Newdow said in the letter last month to the Supreme Court's marshal that he was not making the request as a lawyer but "merely as a parent who seems to have no other recourse in having his child join him in what will be a truly momentous occasion in both of their lives."

The case is being heard without one of the court's most conservative members, Justice Antonin Scalia, who recused himself after making public comments about the case. Scalia did not take part in the decision Monday to allow the mother, Sandra Banning, to file arguments opposing Newdow.

Banning, represented by Washington lawyer Kenneth Starr, maintains that her daughter does not mind saying the Pledge of Allegiance (search).

"It is not only appropriate but important for the court to hear from both parents, especially since Sandra Banning approves entirely of the Pledge of Allegiance as a patriotic exercise at her daughter's school," Starr said Monday.

Dennis Hutchinson, a Supreme Court expert at the University of Chicago Law School, said the case brings drama to the high court.

"This symbolically is a big deal. Everybody understands it," he said.

The case is Elk Grove Unified School District v. Newdow, 02-1624.