Archaeologists have warned the prime minister that without urgent repairs the mount's southern wall and buildings attached to it - including the al-Aqsa mosque - could collapse on some of the hundreds of thousands of Muslim worshippers who are expected to visit during Ramadan, which begins next month.

But Muslim religious authorities have told the Israelis not to touch the wall, saying such that a move would be interpreted as an attempt to assert control over the site.

The issue is all the more sensitive because it was Mr Sharon's controversial visit to the Temple Mount - which is also a holy site for Jews - that provoked the start of the Palestinian intifada two years ago.

The bulge is more than 30 metres long and protrudes by about a metre.

Some archaeologists have compared it to a slow pregnancy. "A year ago you could barely see the bulge," said Dr Eilat Mazar, a Hebrew university archaeologist. "Now it's much more serious. If it was a 'four month' bulge back then, now it's an 'eight month' bulge.

"There's no doubt that it will collapse before long. The question is by how much, and whether it will bring down other structures nearby, including the al-Aqsa mosque."

Israel claimed sovereignty over the Temple Mount after capturing East Jerusalem during the 1967 war, but it has left de facto control to the Wakf Muslim religious trust. However, until recently, the Wakf denied that there was a serious problem.

Mr Sharon met Jerusalem's mayor, the city's police chief and the director of Israel's antiquities authority this week to discuss whether the government should act unilaterally and repair the wall.

Israeli officials acknowledge that acting without the agreement of the Wakf could provoke Palestinian riots, but it also fears violence if the government restricts visits to the Temple Mount during Ramadan on safety grounds.

Wakf's director, Adnan Husseini, accused the government of using the bulge to try to assert control over the mount.

"The Israeli side is trying to make from this problem a very dangerous political issue. They want to gain a foothold," he told the Voice of Palestine radio.

Some archaeologists blame Wakf for causing the problem with the wall by converting an adjacent ancient building inside the mount, known as the Stables of Solomon, into the largest mosque in Jerusalem. Most of the worshippers who visit at Ramadan are expected to pray at the mosque, which has the damaged area as its southern wall.

The lack of cooperation has meant that Israeli experts have been unable to inspect the inside of the wall, and Wakf cannot gain access to the outside, which is shielded by sheeting and guarded by Israeli police.

Mr Husseini says Wakf has attempted some repairs, but claims that the Israeli government has effectively blocked the religious trust.

"The Israelis are hampering the work in accordance with instructions from the highest echelons," he said. "The Israeli authorities bear the responsibility for any loss of lives from a collapse of the wall."

A small group of Jews has urged Mr Sharon not to repair the wall because they say its collapse would destroy the "pagan Arab presence on the Temple Mount".