The Syrian government will resign on Tuesday and a new cabinet will see the light within 24 hours, a high-ranking official in Damascus told AFP.
"The government will tender its resignation today and a new cabinet should be formed within 24 hours," the official said on condition of anonymity.
Syria has been gripped by a wave of deadly dissent since mid-March which has put President Bashar Al-Assad under unprecedented pressure as protesters call for reforms.
Assad, who rose to power in 2000, is expected in the days to come to address his people to announce the end of a state of emergency in Syria, in force since the ruling Baath party took power in 1963.
Prime Minister Mohammed Naji Otri formed his government in 2003 and it was last re-shuffled in April 2009.
Thousands of supporters of Syrian President Bashar Al-Assad poured into central Damascus in a show of support for their leader, who is facing unprecedented domestic pressure amid a wave of dissent.
All roads leading to Sabeh Bahrat ("Seven Seas") square in Damascus were cut off by police armed with batons, as men, women and children raised Syrian flags and pictures of Assad and his father, late president Hafez Al-Assad.
"The people want Bashar Al-Assad," they chanted in unison, under a massive picture of their blue-eyed president that had been hoisted on Syria's central bank.
"We are here to show the real will of the Syrian people, and that is to protect and supporter their president, may God protect him," said a young woman named Raghad, who turned out early for the rally with her sisters.
"This rally is to stop the plot to destroy Syrian unity," said a man who identified himself as Abu Khodr. "Bashar Al-Assad is the spine of Syria. Without him, our country will be pushed into chaos."
The rally comes after a pledge by the authorities to lift the state of emergency in force since the ruling Baath party took power in 1963, sparked by two weeks of increasingly violent protests against the rule of Assad.
Assad, who came to power in 2000, is expected to address his people in the days to come and announce a string of reforms.