"Victory will be another step in what we are doing: modernising Italy through reforms," he said, answering a British journalist's question on whether Premier Matteo Renzi had gambled on calling the Constitutional referendum.
"In the past we have had very difficult years for our economy and the functioning of the institutions, we are gradually emerging from the economic difficulties but we need institutional reforms too,
"That is why we are having the referendum and I'm confident that we will win," Gentiloni said.
The referendum will require Italians to say "Yes" or "No" to a reform that would end Italy's unusual "perfect bicameralism" by turning the Senate into a regionally based body with limited powers.
ANSA