Egypt's cabinet has offered to resign after three days of mass protests against the country's military rulers.
The ruling generals have opened crisis talks with civilian political leaders following the move.
Cabinet spokesperson Mohammed Hegazy said the resignation had not yet been accepted by the military council.
Thousands of protesters remained in Tahrir Square overnight on Monday after a call for further mass demonstrations to take place on Tuesday, the BBC reports.
More than 20 people have been killed and nearly 1800 injured in the violence.
The clashes began on Saturday between police and protesters who want the military to transfer power to a civilian government.
"The government of Prime Minister Essam Sharaf has handed its resignation to the Supreme Council of the Armed Forces," Mr Hegazy said.
"Owing to the difficult circumstances the country is going through, the government will continue working until the resignation is accepted."
A military source told the BBC the council was meeting to discuss the cabinet's offer, but there was still no consensus on whether to accept it. The same source said the council was also consulting with other political groups.
The BBC correspondent in Cairo says the crowds in Tahrir Square cheered and shouted "God is great" when they heard of the resignation.
However, they soon resumed an earlier chant of "the people want the removal of the marshal" - a reference to Field Marshal Mohamed Tantawi, who heads the Supreme Council of the Armed Forces.
He has the task of overseeing the country's transition to democracy after three decades of autocratic rule under Mr Mubarak.
The ruling generals are the real focus of demonstrators' anger, with the interim cabinet seen as having little power.