Some two to three thousand people gathered in the Central African Republic's capital, Bangui, on Friday to show support for the new constitution.
If approved on Sunday's referendum, the constitutional changes open the door for president Faustin Archange Touadéra, to stand for another term.
"In order to triumph? We have to go to the ballot box and vote. We must not stay at home, we must come to vote for the new Central African constitution. Let's leave our occupations behind and come out in massive numbers to vote for the 'yes' to this project", said the national director of the referendum campaign, Evariste Ngamana.
The proposed constitutional change would raise the presidential term from five to seven years, and scrap its two-term limit.
"The people behind the constitutional reform process have proved that they are determined, despite the rain, to be there to prove that what we committed to at the outset what will be borne out in practice", added Hyppolite Robert Ngaté, national coordinator of the Cercle de Réflexion pour une Constitution Républicaine (think tank for a republican constitution, Ed.).
Around 1,9 million electors are eligible to take part in Sunday's referendum.