The Georgia Board of Pardons and Paroles on Tuesday said that the execution of Troy Davis will take place as per schedule at 7 p.m. on Wednesday.

The parole board, which is the only authority in the state with the power to commute a death sentence, has denied Davis’ last-minute plea for clemency on Tuesday morning.

Davis was scheduled to die at Georgia Diagnostic and Classification Prison near Jackson, Ga. by lethal injection on Wednesday night.

The board has considered the totality of the information presented in this case, and thoroughly deliberated on it ... After which the decision was to deny clemency, board spokesman Steve Hayes said in a terse statement.

After the parole decision the Rev. Marvin Morgan went to the board offices in downtown Atlanta and chained himself to a flagpole, protesting Davis’ execution, before police cut him free and arrested him.

If the state of Georgia can intentionally kill a person in a case surrounded with this much doubt, then we're all subject to the same fate, the Los Angeles Times reported, quoting Morgan.

Davis' lawyers on Monday pleaded to the five-member Georgia State Board of Pardons and Paroles to grant clemency to him by making a three-hour presentation to the board, after which attorney Stephen Marsh said: We believe we have established substantial doubt in this case.

According to Georgia law, only the Georgia State Board has the authority to decide whether to grant clemency.

However, prosecutors and relatives of Savannah Police Officer Mark Allen MacPhail also requested the board to carry out the sentence.

The 42-year-old Davis has long professed he's innocent of killing off-duty police officer Mark MacPhail in 1989 in Savannah, and his looming execution has gained international attention since no physical evidence was presented against him during trial. Multiple witnesses have recanted or changed their stories in the years after the murder.

Davis was 19 years old when he was arrested for the murder. Eyewitnesses' statements, two years later, influenced a jury to sentence him to death.

MacPhail, 27, was working as a security officer outside a Savannah bus station on Aug. 19, 1989, when he interfered in an argument between several men and was shot in the heart and face.

I will never have closure, Anneliese MacPhail, the slain cop's mother, told CNN. But I may have some peace when he is executed.

Davis' execution decision was postponed for the fourth time in four years when the parole board announced Monday that it would not take an immediate decision on clemency.

High-profile supporters of Davis include former U.S. president Jimmy Carter. Protests have been held throughout Georgia and elsewhere, including New York, Washington, Los Angeles and around the globe.

Jonathan Perri, a senior organizer on criminal justice for Change.org, which helped organize a campaign to save Davis, said the case is unique for the broad support it has generated.

Davis remained silent throughout his trial and maintained his innocence. Davis was convicted at a 1991 trial on the basis of nine witnesses who all said they saw him shoot the police officer and two others. They said that Davis had confessed the murder to them.

But in the years since the trial, many witnesses have said they were pressured by investigating police officers to implicate Davis.

The pardons board spent several hours on Monday listening to testimony from supporters of Davis, including family and friends.

After the closed door hearing, MacPhail's family said they asked the board to reject Davis' clemency attempt so they can finally have peace.