Hundreds of people protested Saturday in Tunis against a draft constitution put forward by President Kais Saied, demanding his resignation two days before Tunisia votes on the disputed charter.
The referendum will take place a year to the day after Saied sacked the government and suspended parliament in a decisive blow against the country's often chaotic young democracy.
"Get out", the demonstrators yelled as they waved Tunisia's red-and-white flag at a gathering on Habib Bourguiba Avenue in the capital.
"The people want the fall of Kais Saied; the people want the fall of the constitution," chanted those who rallied in response to a call by the National Salvation Front (FSN) opposition alliance.
Among the demonstrators, who numbered fewer than 1,000, were elected officials of the Islamist-inspired Ennahdha party, the political rivals of Saied.
Tunisia is preparing to vote Monday on a draft constitution that would enshrine the vast powers that Saied has exercised since he sacked the government and suspended parliament on July 25 last year.
His move was seen as a decisive blow against the crisis-ridden political system in Tunisia, and his rivals allege his constitution aims to restore an autocracy.
"A year has passed and Saied has failed to manage the country and present a clear vision," Imed Khemiri, spokesman for Ennahdha, told the crowd.
Ahmed Nejib Chebbi, a veteran opposition figure, also addressed the gathering that was closely monitored by police.
"Saied will get a good slap on Monday because the people will show him they're not interested," he said.
The new text aims to replace the mixed presidential-parliamentary system enshrined in a 2014 constitution, which saw Tunisia praised as the sole democracy to emerge from the 2011 Arab uprisings.
The leader of Saied's "new republic" would have ultimate executive power and would appoint a government without the need for a confidence vote in parliament.
The president would also head the armed forces and appoint judges, who would be banned from striking.
Opponents have called for a boycott of Monday's referendum, but while observers have predicted most Tunisians will snub the poll, few doubt the charter will pass.