President Kais Saied attended a cabinet meeting in the capital Tunis, on December 13, 2021. AFP
In a speech on national television, Saied announced a "popular consultation" with the Tunisian people and said that "other draft constitutional and other reforms will be put forward to referendum on July 25".
That will mark a year since he sacked the government, suspended parliament and seized a string of powers.
His move came as the North African country wallowed in political and economic crises compounded by the coronavirus pandemic.
He later moved to rule by decree.
Saied, who has been a sharp critic of the North African country's 2014 constitution, said Monday that a nationwide public consultation would take place from January 1 until March 20 to gather suggestions for constitutional and other reforms.
A committee will then examine them until June, ahead of the referendum on the anniversary the Tunisian republic was declared after independence from France.
Parliament will stay suspended until "elections take place under new laws on December 17 next year", he said.
Earlier Monday, Saied had told cabinet that constitutions are "not eternal".
"The people exercises its sovereignty in the framework of the constitution," Saied said.
"So if it's not possible for the sovereign people to practise its rights in the framework of a text, then there needs to be a new text."
The 2014 constitution, which put in place a hybrid presidential-parliamentary system, was seen as a compromise between powerful Islamist-inspired party Ennahdha and its secular rivals.
But many Tunisians see the political system it created as having failed, creating corruption and endless blockages without resolving deep social and economic problems.