By James Mackenzie
ROME (Reuters) - The leader of Italy's anti-establishment 5-Star Movement rounded off a three-day party rally on Sunday with renewed calls for a referendum on the euro and an angry attack on Prime Minister Matteo Renzi's labour reform plans.
Beppe Grillo, the provocative former comedian who founded the 5-Star Movement and captured more than 25 percent of the vote in last year's national election, said the party would begin a campaign to gather 3 million signatures to call a popular referendum.
"We'll launch a popular law to get us out of the euro," he told a crowd filling the Circus Maximus in central Rome. "We have to take back the Bank of Italy which can start printing lire again." He challenged other Eurosceptic parties, including the anti-immigration Northern League, to join the initiative.
Over the past three days, hundreds of thousands of supporters have filled the ancient open-air chariot racing arena in an event halfway between a music festival and a party congress.
"We are getting back our soul," Grillo said, in a veiled acknowledgement of the loss of momentum suffered by the movement following its election triumph in 2013, which established it as the main opposition force in Italy.
"We cannot be an institution. We are a cause which has burst out across the whole of Italy," he said.
The arrival in February of Renzi, whose mastery of public relations matches Grillo's own, has taken some of the media spotlight away from the 5-Star Movement.
The party has also struggled to impose itself in parliament.
Not only has it refused to create alliances with other opposition parties, it has also been largely sidelined by Renzi's frequent cooperation with Silvio Berlusconi's centre-right Forza Italia party.
However, recent opinion polls show it has maintained solid support at about 20 percent. That is comfortably ahead of Forza Italia but behind Renzi's centre-left Democratic Party (PD), which won almost 41 percent in European elections in May.
FIERY ATTACKS
Chronic political scandals and a deep economic crisis that has put millions out of work and left many young people in uncertain temporary jobs have created fertile terrain for the 5-Star Movement.
In a fiery series of trademark attacks, Grillo laid into targets ranging from biased journalists and television talk shows to traditional parties and the role he said was played by Freemasons in the gas supply industry.
He mocked Renzi as a "leader without followers" after recent reports showing a sharp fall in PD membership, and attacked the government's Jobs Act, aimed at making the labour market more flexible, which has taken its first step through parliament.
Grillo claimed it had been inspired by German legislation aimed at getting the unemployed back to work through part-time "mini jobs", which he said had already proved ineffective.
"The Jobs Act is an economic law that Germany made, not us," he said. "It's an enormous piss-take that didn't even work in Germany."
However, signs of recent tensions in the movement were apparent in a dispute between Grillo and Federico Pizzarotti, the 5-Star mayor of Parma who has criticised the party leadership and who was not invited to speak on stage.
(Reporting by James Mackenzie; Editing by Aidan Martindale)