By Mohamed Fadel Fahmy, CNN

Coptic Pope Shenouda III, the spiritual leader of Egypt's Coptic Christian community, is in deteriorating health, the head of the Egyptian General Coptic Association said Tuesday.

Shenouda, 88, "suffers from kidney disease and diabetes," said Sherif Doss, but said he was still "functional."

Bishop Basanti of Helwan governorate denied rumors that the pope is in a coma.

"He is well and under good medical care," the bishop insisted, saying that he would give his regular weekly address Wednesday evening.

Egypt's population is roughly 9% Coptic Christian, according to the U.S. State Department.

The Christian minority has been the subject of a number of high-profile attacks in the last several years, including the bombing of a major church in Alexandria last January that left at least 21 people dead.

Doss said he would expect 2 million Coptic Christians out on the streets for Shenouda's funeral when he dies, but predicted there would be no violence.

Shenouda has been in poor health on and off for many years.

"He has been leading the church for 38 years and is a beloved man that is highly respected," Doss said.

The Coptic Orthodox Church is the largest Christian church in the Middle East, according the Coptic Orthodox Church Centre in England.

In addition to millions of followers in Egypt, the church has adherents in Europe, Canada, the United States, Kenya, Zimbabwe, Namibia and South Africa, the center says.

When a Coptic pope dies, all 150 bishops of the church's Holy Council appoint an acting patriarch until a vote is conducted for a successor, Doss said. Thousands of bishops, priests, and monks are eligible to vote.

The most senior bishop usually takes the role of acting patriarch. In this case, that would be Bishop Michael of Asiut. If he declines, Bishop Bakhamious of Behira is next in line, Doss said.