Tunisian President Kais Saied has issued a decree calling voters to a referendum on a new constitution on 25 July.
There will be one question on whether people agree with the new constitution, according to an official notice.
It said that the polls will start at 06:00 to 22:00 local time.
It comes after he named an advisory committee to draft a new constitution for a “new republic” amid opposition’s calls to reverse the move.
The country’s main political parties say they will boycott dialogue on the formation of the new constitution and term the president’s action unilateral.
Mr Saied has pushed through a series of moves expanding his powers and dismantling elected institutions since last year, when he suspended parliament.
He announced the plan for a “new republic” earlier this month.