In an unprecedented judgement, the court ruled that Nasser Hamed Abuzaid, a professor at Cairo University, was an apostate because he "published studies and research attacking Islam and inciting disrespect for Islam's rulings on tradition".Therefore, it was argued, he could not remain bounded by marriage to his Muslim wife, Ibthial Yunis-Abuzaid.
The decision overturned a lower court ruling in January last year that the plaintiffs, who first brought the suit in March 1993, were "unqualified" to raise the case.
The original case against Professor Abuzaid, 52, was raised by Semmeidah Abdulsammad, an Islamic fundamentalist lawyer representing Gammat-al-Hissbah, a voluntary group that brings private prosecutions against alleged anti- Islamic activities. It aims to form a citizens' arrest group along the lines of Saudi Arabia's religious police.
The case was filed after Cairo University initially refused to grant a professorship to Mr Abuzaid, who attended religious schools in his youth. The university committee, which liberals say has been hijacked by fundamentalists, ruled that his books on Islamic law were heretical. But a second university committee reversed the decision and granted Mr Abuzaid the position at the end of last month.
The professor is one of several Egyptian intellectuals who have spoken strongly in public against extremists and the conservative trend of Islamic thought. He has been an outspoken critic of Muslim scholars and academics - one of them an influential member of the Cairo University committee - who used Islamic dogma to encourage ill-educated Egyptians to invest their life savings in Islamic banks. The investors eventually lost their savings.
Last night Mrs Abuzaid, a 37-year-old Cairo university professor of French literature, was angry and frightened. "I can't collect my thoughts from what feels like a blow to the head with a stone,'' she said, adding that her husband was too upset to talk to the press.
"My husband and I will ask for political asylum in any nation. We will not stay here waiting for some bearded Islamists to attack us," she said.
The Abuzaids have the right to appeal against the sentence.
"That could take eight or nine years and I am afraid for our lives," Mrs Abuzaid said.
Some Cairo lawyers were confused by the ruling, since Egyptian civil laws and statutes, which are largely based on French laws, make no reference to heresy.