A demonstration was planned for Sunday in the mosque yard after calls by Taysir al-Tamimi, Palestinian chief judge, to protect it from Israeli development plans.
He said: "I have appealed to all Palestinians to head on Sunday towards the holy Al-Aqsa mosque to hinder the Israeli order to demolish parts of the western fence of the holy al-Aqsa mosque."
"Israel is now carrying out wide excavations under the mosque and is building a synagogue in front of the Dome of the Rock," al-Tamimi said, adding the mosque was seriously threatened and could collapse.
Israel occupied and annexed the compound containing the holy sites after the 1967 Arab-Israeli war.
The annexation of the compound is not recognised by international law. The al-Aqsa and Dome of the Rock mosques sit above the Western Wall, Judaism's holiest site.
The al-Aqsa mosque is Islam's third holiest shrine.
The area is referred to by Muslims as al-Haram al-Sharif and by Jews as the Temple Mount.
Al-Tamimi said appeals had been made to Islamic and Arab states, the OIC, the Jerusalem Committee and the Arab League to intervene, but to no effect.
"Unfortunately, none [of these nations or bodies] has done anything as it seems that Jerusalem, al-Aqsa mosque and Palestine are not on their agendas."
For his part, Khaled Meshaal, the political bureau chief of Hamas, on Sunday condemned excavations by Israeli archaeologists near Jerusalem's al-Aqsa mosque, as Israeli security restricted access to the site.
"Israel knows what its violation of the holy Aqsa will bring. It is playing with fire," Khaled Meshaal said on Sunday at a news conference in Syria, where he lives in exile.
Meshaal warned that further Israeli threats to the integrity of the mosque would be considered inflammatory. He said: "Sharon's desecration of the Aqsa sparked the 2000 uprising.
The Israeli leadership must learn from this lesson. We have confidence in our people, its masses, all of its groups and military wings.
"We are facing a dangerous action.
Jerusalem's Muslim and Christian holy sites are dear to all Palestinians. Israel is trying to take advantage of the Palestinian internal conflict to commit its crimes."
A visit to al-Aqsa mosque compound in September 2000 by Ariel Sharon, then Israel's opposition leader, led to the second Palestinian intifada.