Renzi has staked his leadership on the controversial referendum, which some experts say could have a more detrimental impact on the EU than Brexit.
The vote intends to bring about reforms that would streamline Italy's political system, which would save money, allow laws to get passed quickly, and stabilize future governments.
But with many failing to grasp Italy's complex political systems, the vote could be a chance for people to simply say "Yes" or "No" to Renzi as the country's leader.
Despite tensions even within his own Democratic Party, Renzi said last week that he is confident his government will win the referendum.
“I am sure we (will) win,” he told CNBC news.
“This referendum is about the future of the country and I am sure the Italian people, if (they) read the question in the ballot in the electoral place, will vote for change."
In a report last month the political risk consultancy firm, Eurasia Group, said the referendum had a 60 percent probability of passing, but added that the polls have narrowed sharply since April.
A ‘No' vote could cause Renzi's government to collapse, the report added.
"A debilitated Renzi would come under intense pressure to resign; he may himself not wish to cling on to power."
The vote is expected to be held in either October or November.