The patriarchs also issued an unusual appeal asking for Christian representation at the Camp David summit, should it continue, as well as in any future peace talk forums.
"We appeal to you as foremost political leaders and negotiators to ensure that the Christian communities within the walls of the Old City are not separated from each other," said the open letter addressed to President Bill Clinton, Israeli Prime Minister Ehud Barak and Palestinian President Yasser Arafat.
"We regard the Christian and Armenian Quarters of the Old City as inseparable and contiguous entities that are firmly united by the same faith. Furthermore, we trust that your negotiations will also secure that any arrangement for Jerusalem will ensure that the fundamental freedoms for worship and access by all Christians to their holy sanctuaries and to their headquarters within the Old City are not impeded in any way whatsoever."
The letter was signed by Diodoros I, Jerusalem's Greek Orthodox patriarch; Michel Sabbah, the Latin (Catholic) patriarch, and by Armenian Patriarch Torkom Manoogian II. The three leaders head church denominations that represent the overwhelming majority of the estimated 12,000 Christians living in Jerusalem, as well the majority of Christians living in Israel and the Palestinian Authority.
The letter was apparently triggered by news reports that both Israel and the Palestinian Authority had softened demands for total sovereignty over the historic Old City, and were now considering some division of powers.
According to one plan reportedly being considered by the Palestinians, Israel would continue to control the Jewish Quarter and the adjacent Armenian Quarter while the Palestinian Authority would take control of the Muslim quarter and the adjacent Christian quarter.
The area known to Jews as the Temple Mount and Muslims as al-Haram al-Sharif, and which now contains the Al Aksa and Dome of the Rock mosques, would belong to the Palestinian sphere, while the Western Wall plaza just below would remain under Israeli control.
The Western Wall is the retaining wall of the ancient Jewish Temple that stood on the mount during the era of the Biblical King Herod.
Such a division of the Old City's historic quarters could potentially sever Jerusalem's tiny Christian Armenian community of an estimated 2,000 people from the remaining Christian population in the Old City.
In their letter, the Christian leaders suggested that as an alternative to the physical division of the Old City, they would prefer to see international guarantees ensuring free access by Jews, Muslims and Christians to their Jerusalem holy places.
"We suggest one possible way of ensuring this peaceful unity and cohesive prosperity of the Christian presence in the Holy City of Jerusalem is through a system of international guarantees that will ensure to the three religious communities a quality of right of access to their respective holy places, of profession of faith and of development," the letter said.
"It might well be advisable to have representatives from our three Patriarchates and the Custody of the Holy Land (the Vatican) at the Camp David summit meeting as much as at any future forum in order to provide continuity and consultation on our future and on our rights, so that our one collective presence here with its history of rights and expectations is maintained unequivocally and safeguarded fully," the letter said.
Observers said that the letter clearly represents an attempt by Christian communities to "close ranks" at a delicate moment in the peace process, when Muslim and Jewish religious concerns, rather than the interests of the Christian communities, may in fact be the determining factor in the success of the Camp David talks.
"The churches are positioning themselves for any eventuality," said Rabbi David Rosen, head of the Israel Office of the Anti-Defamation League.
Still, it is highly unlikely that either Israel or the Palestinians will grant Christians, or any other religious group, separate representation in their peace delegation or in summit talks, he said.
"I think that there have been talks between religious leaders on what kind of constructive role they can play after a political settlement. But neither Israel, nor the Palestinian political leadership have an interest in introducing religious authority into the political negotiations," said Rosen.