The Israeli government, fearful that a rush of pilgrims marking the new millennium next year will turn Christendom's holiest shrine into a death trap, is putting pressure on the religious orders which control it to open a new emergency exit.
The Church of the Holy Sepulchre in Old Jerusalem is where Jesus is believed to have been crucified and buried. Its only entrance has been guarded for 700 years by two Muslim families - the Nusseibeh and Joudeh clans - who have locked it at night and kept the ancient key safe.
A final decision on a new door has yet to be taken by the often antagonistic religious orders which share control of the church. But the tradition of the sole gatekeepers who have kept the peace for centuries is under threat.
The "breakthrough" paving the way for what Israel hopes will be a millennial tourism windfall was said to have been made at the weekend.
The tourism minister, Mr Moshe Katsav, issued a statement claiming that the three churches which occupy the Holy Sepulchre - Greek Orthodox, Armenian and Roman Catholic - had agreed to decide the location of the new door by the end of this month.
The statement said it would be close to St Helena's church, a shrine built on the roof owned by the Egyptian Copts. But access is via a monastery, Deir Sultan, belonging to the Ethiopian church.
Every inch of the Holy Sepulchre is a source of dispute between the churches. So when Mr Katsav spoke it came as no surprise that the churches remained silent.
According to the Israeli government, a committee which has been meeting for eight months, which includes the churches, the tourism and religious affairs ministries and police, also agreed that the key to the new entrance would be held by the churches. The government had apparently wanted custodianship of the key, but the churches refused.
The Holy Sepulchre once had more than 10 entrances. When Salah a-Din conquered Jerusalem in 1178, he ordered all of them sealed except for the Crusader gate, which today serves as its only door, and he entrusted the key to the two families.
Mr Wajeeh Nusseibeh (49), who opens the church every morning at four, was trying to preserve his dignity yesterday as journalists badgered him about a decision of which he knew nothing. "Maybe it's just a balloon the Israelis are floating," he said.
"They keep talking about all these pilgrims that are going to come, but in all my years here I've actually never seen fewer visitors."
The church was indeed almost deserted. Mr Nusseibeh inherited the custodianship from his father 20 years ago and now his own son Obada, 17, accompanies him on his unpaid duties.
Salah a-Din gave the family 40,000 dunams (about 10,000 acres) of land near the West Bank city of Nablus. They still earn an income from some of it, although much of the land has been confiscated by Israel to build Jewish settlements.
Mr Nusseibeh explained that the division of duties meant the Joudeh family looked after the key at night.
"Nobody has asked us about this plan, neither the churches nor the Israeli government. It should be discussed by [the Palestinian Authority President] Yasser Arafat."
Jerusalem's Old City has been occupied by Israel since 1967 and its status, along with that of the holy sites of Christianity and Islam, is among the thorniest issues in peace talks.
Mr Nusseibeh said he would abide by any democratic solution but could furnish documents, dating back centuries, to prove his role.
"We are simple people and proud to serve in the holy places. We may be the bridge of peace between Islam and Christianity and the friendship between everybody," he said.
Many factors could yet derail the agreement. "It's not a question of the key only," said the Rev Claudio Baratto, a Franciscan monk who represents the Roman Catholic church.
Not least is the consent of the Ethiopians, who were forced out of the main body of the Holy Sepulchre in the 17th century when they could not pay high Ottoman taxes, and retreated to the roof. The quiet dignity of their monastery is at odds with the sectarian tensions beneath their feet.
Mr Gabra Selassie, accountant to the Ethiopian Patriarchate, said it was agreed that another door should be opened.
"But this plan is not good because it's in our place, and so we are opposed to it," he said. "There are many other corners, many other doors bricked up, that could be opened. The Israeli government must look to the other side."
Yet he did leave open the possibility of a deal allowing the Ethiopians to return to the church's interior. At the very least he would insist the new key be kept by the Ethiopian monks.
The chances that everything can be resolved by the end of this month are not good. Some believe the Israelis are exaggerating the dangers for strategic and territorial purposes.