COLUMBIA - The S.C. Supreme Court will consider next month whether Gov. Mark Sanford is ineligible to serve because he is an Air Force Reserves officer.

Edward Sloan Jr., a retired Greenville construction company owner, said the state Constitution prohibits Sanford from holding both positions at the same time.

"I am a supporter of the governor, but I don't see a conflict between that and defending the constitution," Sloan told The State newspaper on Wednesday.

Sloan, 74, is a self-described government watchdog who has sued other public agencies and groups. Two years ago, he sued the caretakers of the Confederate submarine H.L. Hunley to force the group to disclose its financial dealings.

In Sanford's case, Sloan filed a petition directly to the state Supreme Court earlier this year without seeking lower court rulings. The high court accepted the case under its "original jurisdiction" power, which allows for first-time review of strictly constitutional questions.

The justices will hear arguments in the case Dec. 3. A ruling will be issued later.

Sloan's lawyer, James Carpenter, said a ruling in his client's favor could have "far-reaching" implications. The justices could invalidate last year's gubernatorial election and any laws signed this year by Sanford, he said.

But Sloan's court petition does not call for a broad ruling.

Sanford, in court papers, indicated he wants a narrow court ruling, limited to the question of whether he can hold both positions simultaneously.

Sanford spokesman Will Folks said the governor "very much wants to continue honoring his military commitment."

In court papers, Sanford said he believes he can serve both as governor and as an Air Force Reserve first lieutenant. He said that although the state constitution bans the governor from holding "any office or other commission," it makes an exception for service in the "militia," which he contends includes the Air Force Reserve.

Sloan says in court papers that a "militia" refers only to a state citizen-soldiers group, not to a U.S. military reserve branch.

Every state Constitution since 1776 has banned the governor from holding other positions while in office, Sloan said.

"From that day to this, South Carolinians have required their governor's singular and devoted attention to his office and to this state," he said in court papers.

Sanford also said in court papers that Sloan's case should be dismissed because Sloan does not have legal standing to bring the issue to court.

Earlier this year, Sanford spent two weeks at a Reserve officers' training course in Alabama. He received his reservist commission in January 2002, about a year before he took office as governor. He continues to participate in monthly drills and would be obligated to serve if he were called to active duty.