Georgia officials rejected an appeal for clemency for a death row inmate deemed to be mentally retarded by the state court system, setting the stage for his execution on Wednesday unless the U.S. Supreme Court intervenes.

Lawyers for Warren Lee Hill, Jr., asked the Georgia State Board of Pardons and Appeals to commute his sentence to life without parole. Hill, 52, is set to die by lethal injection for beating his cellmate to death in 1990, when he was already serving a life sentence for the 1986 murder of his girlfriend. However, on Tuesday morning the board denied the request, as well as the defense team's appeal for a 90-day stay of execution. The board denied the petition with little comment, simply saying in a statement that after considering the request, the board has voted to deny clemency.

In a statement, Hill's attorney Brian Kammer said the decision was a violation of basic moral values as well as state and federal laws.

This shameful decision violates Georgia's and our nation's moral values and renders meaningless state and federal constitutional protections against wrongful execution of persons with mental disabilities, Kammer said.

Kammer is filing an appeal with the Supreme Court in a last-ditch effort to stall the execution.

Tests have shown that Hill has an IQ of about 70, putting him in the range of people with mild mental retardation.

Hill's petition for clemency reportedly included a statement from two of his former elementary school teachers who said it was obvious to them that he was mentally disabled. According to the Atlanta Journal-Constitution, the teachers said at that time Hill could not read or write at grade level, did not interact with peers and was virtually non-communicative.

Neither of the juries at Hill's two trials were informed that he displayed signs of learning disabilities, or that he had an IQ of 70. In 2002, a Georgia judge found Hill to be mentally retarded.

The judge's finding was made shortly after the Supreme Court in 2002 banned the death penalty for mentally disabled inmates in Atkins v. Virginia, when the court ruled that executing mentally impaired death row inmates violated the U.S. Constitution's ban on cruel and unusual punishment. However, it left it up to the states to decide who falls into that category.

Georgia, rather paradoxically, was the first state in the U.S. to ban the execution of inmates with learning disabilities, in 1988. But it also requires that impairment be proved beyond a reasonable doubt, according to the Death Penalty Information Center, setting the bar higher than any other state.

The state attorney general's office said in a statement that Hill's lawyers failed to adequately prove the defendant is mentally disabled, despite the 2002 ruling in which a state judge agreed that a preponderance of evidence indicated Hill was impaired. The Georgia Supreme Court overturned the decision in 2003.

Several prominent death penalty opponents, including former President Jimmy Carter and his wife, Rosalynn, have objected to Hill's imminent execution. The Carters reportedly wrote to Georgia's board of pardons to request clemency for Hill, arguing that in light of the evidence indicating Hill's mental disabilities, his execution would undermine Georgia's historic leadership in promoting the rights of the developmentally challenged.

This week, France also made an appeal for Hill's life. Bernard Valero, a spokesman with the French ministry of foreign affairs, told Radio France Internationale the European nation made its appeal to the state of Georgia as a first step to abolishing the death penalty, worldwide. Capital punishment was officially abloshed in France in 1981, which held its last execution in 1977.

In a June 18 letter to the state parole board, Richard Handspike, whose uncle was the inmate killed by Hill in 1990, said if prosecutors had contacted his family about their decision to seek the death penalty the family would have opposed it.

Handspike, the Atlanta Journal-Constitution reports, told the board his family feels strongly that persons with any kind of significant mental disabilities should not be put to death.