In a joint letter, the bishops told Lusaka that the HIV/AIDS pandemic had "increased absenteeism, reduced teacher numbers and adversely affected the quality of teaching."

"The HIV/AIDS pandemic therefore represents one of the most urgent challenges to our nation and especially to our educational system," the bishops said.

One in every five Zambians is said to be HIV positive.

The bishops called for more funds in education, saying poor infrastructure had led to "unacceptable standards in the learning environment."

"We appeal that decisions made by the government on educational policy be based on sound educational principles rather than political expediency," Bishop James Spaita said at a news conference while reading the open letter signed by nine others.

"Quality education does not come cheap. We call on the government to give real priority to education at all levels," the 16-page letter stated.