The polling company Ixe said Renzi has a 59 percent approval rating, making him the most popular politician in the country, the Italian news agency ANSA reported. Renzi's support has grown by 4 percentage points in a week, Ixe said, while President Giorgio Napolitano trails in the No. 2 spot with 40 percent approval.
But the polling company said almost half of those it surveyed either had no opinion or refused to answer.
Ixe said that almost two-thirds of respondents approved Renzi's plan to use tax cuts and investments to kickstart the Italian economy. Support was high even among the populist 5-Star Movement, with 56 percent backing Renzi, and among followers of former Prime Minister Silvio Berlusconi's Forza Italia party with 68 percent.
Ixe surveyed 1,000 people. The margin of error is 3.1 points.