Notre-Dame Cathedral, a symbol of France, has only a "50 per cent chance" of being fully restored after fire ravaged the iconic building earlier this year.
French President Emmanuel Macron vowed at the time that the cathedral would be rebuilt after the devastating fire in April.
But rector Monsignor Patrick Chauvet told the Associated Press this week that the centuries-old landmark might never be fully restored.
"Today it is not out of danger," Chauvet said.
He explained that scaffolding erected for renovations on the building before the fire broke out poses a risk to the badly damaged structure.
There are some 50,000 tubes of scaffolding at the rear of the cathedral, some of which were damaged by the fire.
Monsignor Chauvet fears that they may fall in on the vaults, exacerbating the damage.
"[The cathedral] will be out of danger when we take out the remaining scaffolding," he said.
"Today we can say that there is maybe a 50 per cent chance that it will be saved.
"There is also 50 per cent chance of scaffolding falling onto the three vaults, so as you can see the building is still very fragile."
Monsignor Chauvet spoke to the AP at a nearby church hosting the Christmas Eve mass due to continued safety risks at the cathedral. It was the first time since the French Revolution that the Christmas Eve mass did not take place inside the cathedral.
Some services have resumed at the cathedral, with priests wearing helmets for their safety, but Monsignor Chauvet said that renovation work is still some way off.
For now, the focus continues to be on stabilising the structure.
"We need to remove completely the scaffolding in order to make the building safe, so in 2021 we will probably start the restoration of the cathedral," he said.
He added: "Once the scaffolding is removed, we need to assess the state of the cathedral, the quantity of stones to be removed and replaced."
