Hundreds of protesters marched on the streets of the Tunisian capital, Tunis, on Friday to protest against the president and the draft constitution.
The demonstrators were met by a heavy police presence including water cannons and riot gear.
According to police sources, at least ten people were arrested.
The new constitution will be voted on in a referendum on Monday.
"I'm worried for Tunisia. I was there for the presidents' Kaïs Saïed power grab on July 25th . I was rooting for a positive change, so that we hold to account the thieves and mafia who have stolen the country. But after his power was reinforced on September 22nd, we saw his true nature. We saw that his problem wasn't combatting the corrupt - and to this day nobody has been found guilty", said Samia Abbou, head of the Attayar party.
Critics claim the new constitution would enshrine the vast powers that Saied has exercised since he sacked the government and suspended parliament on July 25 last year.