ROME (Reuters) - The anti-establishment 5-Star Movement has overtaken Prime Minister Matteo Renzi's Democratic Party (PD) as Italy's most popular party ahead of crucial local elections next month, according to the latest opinion poll.
The Index Research poll, commissioned by current affairs program Piazza Pulita and broadcast on Monday evening, showed 28.4 percent of Italians would now vote for 5-Star in a national election, compared with 28.0 percent for the PD.
The survey is the first one to put 5-Star ahead of the PD after increasing in the polls over the last year as the economy struggles and job growth has been slow.
The trend has accelerated in recent months amid a spate of scandals involving the government and the PD, and Renzi's personal approval ratings have fallen.
At the end of March, Renzi's industry minister resigned in an influence peddling scandal. Last week the PD mayor of the northern city of Lodi was arrested for allegedly rigging public tenders and the party's chief on the island of Sardinia was convicted of tax evasion.
The majority of recent polls have given the PD a lead of between one and four points.
5-Star, founded in 2009 by comedian Beppe Grillo, is especially popular among younger voters. It presents itself as the only movement able to clean up politics and take on vested interests, and wants to hold a referendum to decide whether Italy should remain in the euro.
In June, mayoral elections will be held in Italy's main cities, and pressure on Renzi from PD dissidents will intensify if the party should fare badly in the key contests of Rome, Milan, Naples and Turin.
5-Star has tended to struggle in local elections, which is widely attributed to a lack of organization and well known figures. However, its candidate leads the polls in Rome, where victory would be a huge breakthrough for the movement.
All the main cities are expected to be close contests requiring run-off ballots, and only in Turin does the PD's candidate appear the clear favorite. The Index poll was conducted nationally and not broken down into cities.
The next general election is not due until 2018, but many analysts expect it may be held next year due to instability in Renzi's left-right coalition.
Under a two-round voting system brought in last year, if no party gets 40 percent of the vote in the first round a run-off ballot will be held between the two largest parties.
The Index Research poll put the pro-autonomy Northern League in third place with 13.0 percent of the vote, followed by former prime minister Silvio Berlusconi's Forza Italia (Go Italy!) on 12.6 percent.
(Reporting by Gavin Jones; Editing by Robin Pomeroy)