The BBC's Hilary Andersson: "The planned mosque has caused tensions which have turned violent"

The move was announced in a letter from church leaders in the Holy Land to the Israeli Government.

Leaders of the Roman Catholic, Greek Orthodox, and Armenian denominations said the government was discriminating against Christians by allowing work to begin on the mosque next week.

It said that "all the sanctuaries of the Holy Land will be closed on 22 and 23 November", warning that further action could also be taken.

The tent must come down by Monday

Although the sites were not specified, it was expected that the Church of the Nativity in Bethlehem in the West Bank would be included, as well as the Church of the Annunciation and the Church of the Holy Sepulchre in Jerusalem.

The letter was criticised by local Muslim leaders as provocative.

Salman Abu Ahmed - head of the Islamic Movement in Nazareth, which has been campaigning for the mosque for two years - warned that it would "raise tensions in our relations".

"I can't believe what I am hearing. I thought that religious people were supposed to be more forgiving," he said.

Pope visit under threat

According to Christian tradition, it was in the Church of the Annunciation that the Virgin Mary was told by the Angel Gabriel that she would be giving birth to Jesus Christ. As such, it is considered one of the key Christian holy sites.

Local Christians want to build a plaza on surrounding empty land to accommodate the hundreds of thousands of pilgrims expected to visit the site over the millennium, the 2,000th anniversary of Christ's birth.

Pople John-Paul II's visit could be under threat

Local Muslims however, also lay claim to the ground because it holds the tomb of a revered Muslim sage.

The Israeli Government last month ordered a compromise deal, allowing the mosque to be built on part of the site, after the millennium.

A cornerstone for the mosque is due to be laid next Monday, provided that Muslims remove a temporary prayer tent by the same day.

The issue has caused tensions which erupted into unusual sectarian violence between indigenous Muslims and the Christian minority in Easter.

It is feared that this and recent riots in Bethlehem, following the shooting of a Palestinian souvenir vendor by an Israeli soldier, may deter tourists from visiting the Holy Land over the millennium.