Feb 8 (Reuters) - The legal battle over former Mississippi Gov. Haley Barbour's last-minute raft of pardons will take center stage Thursday morning, when the state's Supreme Court will be asked to block a wave of pardons issued during his final days in office last month.

The Mississippi attorney general, Jim Hood, has filed a lawsuit claiming that many of the approximately 200 pardons are invalid because not enough public notice was given to the communities where the crimes were committed.

Lawyers for each side will present oral arguments early Thursday in a dispute that raises complex legal questions about the principle of separation of powers -- and about the limits of executive and judicial authority.

Legal questions aside, a fierce public debate over clemency broke out almost immediately after Barbour pardoned the convicts, including five men serving life sentences, four of them for murder, who worked at the governor's mansion on prison work release doing domestic duties.

Barbour, a conservative Republican who considered running for the White House last year, has defended the pardons, saying the people receiving them had redeemed themselves, and he accused Hood of trying to score political points.

Barbour's attorneys, along with defense lawyers for several of the pardoned felons, have made a more technical argument. In court papers, they say the governor's power to grant pardons cannot be reviewed by the legislature or the judiciary.

Therefore, they say, the court has no authority to reject Barbour's pardons, whether or not the constitutional provision was met requiring notice of pardons to be published in a newspaper for 30 days beforehand.

"This appeal implicates nothing less than the fundamental structure of our Constitutional Government," wrote Thomas Fortner, a lawyer representing four pardoned defendants, three of them for murder convictions.

But according to Hood, the question is simple: Did Barbour's pardons meet explicit constitutional requirements? The governor's power to decide whether to pardon someone on the merits may be absolute, Hood argues, but he can only put that authority into practice in compliance with the state constitution.

"This court has repeatedly, and for good reason, held that the Governor is not above the law and his acts are reviewable," Hood's brief asserted.

'THIRTY DAYS'

Like many states, Mississippi allows its governor to issue pardons with virtual impunity. The state constitution imposes only a few limits: no pardons may be granted before conviction or for impeached officials; any pardons for treason or any remittances of forfeitures in criminal cases require approval by the Senate; and all pardons must be preceded by 30 days of newspaper publication.

In his brief for the pardoned defendants, Fortner argued that the state constitution's framers could have included an explicit system of review to enforce the 30-day notice provision, as they did by designating the Senate to review pardons for treason and forfeitures.

Fortner also contended that the notice provision is a procedural requirement, and that failing to follow it amounts to "harmless constitutional error."

But Hood relied in part on 19th-century newspaper accounts to argue that the notice provision was intended to protect against executive abuse, and that the court is within its rights to enforce it.

"The framers considered the provision so significant that they waged two floor fights over it at the 1890 Convention," Hood's brief argued. "The Governor's self-interested questioning of the wisdom of the requirement is irrelevant. The Constitution is the Constitution, the law is the law, and a rule is a rule."

Hood pointed out that the constitution also provides no specific review for a pre-conviction pardon, creating the possibility that a governor could pardon a murder defendant during trial without any review by the courts.

"The general rule is clear: the wisdom of a pardon is not reviewable, but the Governor's compliance with the constitutional limitations on his pardon power is," Hood's office wrote.

'51 SYSTEMS OF CLEMENCY'

Some legal observers say Mississippi's pardon dispute can be traced to vagueness in the state constitution itself.

"This whole issue forces an examination of what is in the constitution and its lack of clarity," said Michele Alexandre, a law professor at the University of Mississippi. "The failing here starts with the constitution."

For example, the parties are arguing over whether publishing notice in a weekly paper for four consecutive weeks counts as "thirty days."

Historically, federal and state courts have been exceedingly reluctant to impose any limits on executive pardon power, said Dan Kobil, a law professor at Capital Law School in Ohio who has studied pardons.

The closest comparison to the current lawsuit is when Richard Celeste, a Republican governor of Ohio, issued several commutations and pardons just before leaving office in 1994. A Democratic attorney general, Lee Fisher, challenged the move in court, saying Celeste failed to follow a state constitutional provision that required him to seek the advice of a parole board, even though he was not bound to follow it.

Celeste's attorneys argued that the provision was merely procedural, but the Ohio Supreme Court invalidated one of the pardons based on the constitutional requirement.

Of course, there are "51 systems of clemency" in the United States, Kobil said, and only the Mississippi constitution is relevant here.

"If (the court's ruling) hinges on the express language of the constitution, I think the attorney general has the better of it," Kobil said.

(Reporting by Joseph Ax)

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