President Hosni Mubarak's grip on Egypt looked increasingly tenuous yesterday after the army pledged not to confront protesters who converged in Cairo in their tens of thousands to demand an end to his 30-year rule.

Anti-Mubarak reformists and opposition figures hoped one million Egyptians would join the biggest protest to mark an uprising which erupted a week ago to force Mubarak to step down.

The disintegration of Mubarak's power structure would usher in a new era in modern Egyptian history and reconfigure the geopolitical map of the Middle East, with huge ramifications forWashington and allies from Israel to oil giant Saudi Arabia.

The army, a powerful and respected force in Egypt, dealt a possibly fatal blow to the 82-year-old Mubarak on Monday night when it said troops would not open fire on protesters and that they had legitimate grievances and a right to peaceful protest.

Mubarak's new vice president, Omar Suleiman, appointed to show the government was willing to bring in reforms, offered to open a dialogue with the opposition.

But the measure, along with the dismissal of his cabinet and the promise of reform, appeared to be too little, too late.

"There is nothing that we will accept from him other than he takes the plane and leaves," said Ahmed Helmi, a 45-year-old lawyer, one of thousands of Egyptians flocking to Tahrir Square yesterday to try and to push Mubarak over the edge.

The uprising broke out eight days ago amongst a population fed up with corruption, oppression and economic hardship and quickly spiraled to a crisis unprecedented during 30 years of rule enforced by ruthless security forces.

The United States and other Western allies watched at first in confusion as thousands demanded the downfall of a stalwart ally who has been a key figure in Middle East peace moves.