Protest party leader Beppe Grillo has won the street battle in Italy’s campaign for the European elections, filling Rome’s San Giovanni square for his closing rally on Friday night with a number of supporters that his rivals could only dream about.

It remains to be seen whether his Five Star Movement (M5S) will snatch the biggest prize of all as polls open Sunday: beating the centre-left Democratic Party (PD) of Prime Minister Matteo Renzi to the top spot.

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“This time we are not going to win: we are going to trash them. It’s gonna be different, very different,” Grillo said, speaking in front of hundreds of thousands of people.

In his speech, the comedian-turned-anti-establishment politician said Italy was facing an “apocalypse” of job losses and factory closures, attacked Renzi – whom he refers to as the “little moron” – promised clean politics, universal unemployment benefits, and a referendum on eurozone membership to give back to Italians their “monetary, economic and cultural sovereignty”.

He also rapped about a looming technological revolution – one of his signature themes – based on renewable energy and 3D printers.

Renzi, whose rally on the previous day failed to fill up a smaller square, closed his campaign in his native Florence, before 20,000 people, according to PD estimates.

The going has proven tougher than expected for the ambitious PD leader, who was installed three months ago as Europe’s youngest prime minister, pledging unprecedented economic and political change. He has delivered an 80-euro-a-month tax cut for low-paid workers, but has seen other administrative and electoral reforms getting bogged down.

He was dealt a major blow on 15 May, when data showed that Italy’s GDP had suffered a surprise 0.1 percent fall in the first quarter, confounding expectations of recovery for the eurozone’s third-largest economy, which suffered the deepest recession of its postwar history in 2011-2013.

Until last year, Renzi revelled in the role of the insurgent aiming to shake up Italy’s sclerotic establishment. He has now rebranded himself as the face of responsible government. “You don’t win with fear, politics cannot be made of insults and threats,” he said Friday, taking a shot at Grillo.

In Italy, opinion polls cannot be published in the last two weeks of a campaign, but in recent years websites have sprung up offering rumours from “clandestine horse races” or non-existent Vatican “conclaves” where the names of fictional jockeys and horses, cardinals and bishops, recall those of real Italian political leaders and parties.

The most recent information suggested that the PD would manage a share of the votes ranging from 29 to 34 percent, beating the M5S by a margin as little as one and as big as 8 percentage points. Such data is treated with some caution, as in last year’s general election pollsters consistently underestimated support for Grillo.

Opinions concurred, however, that the conservative Forza Italia of Silvio Berlusconi would be confined to a humiliating third spot, with scant hopes of breaking over the 20-percent mark.

Berlusconi, a scandal-prone former premier, has been hobbled by a tax fraud conviction, which last year earned him an ejection from parliament and a six-year-ban on running for office, and saw him start a one-year community service in a centre for Alzheimer’s patients on May 9.

At the end of a campaign where he outraged Germans by accusing them of being in denial about Nazi concentration camps, compared Grillo to an “aspiring dictator” akin to Stalin, Hitler and Pol Pot, and even promised free dentures to pensioners, the 77-year-old insisted he was down, but not out.

“I will make it, because even if they call me crazy, there are loads of people who are crazy like me,” he said.

Parties have to win at least 4 percent of the votes to win a share of the 73 seats allocated to Italy in the European Parliament.

The anti-euro and anti-immigrant Northern League and the centrist New Centre Right, a junior coalition partner of Renzi, were expected to win up to 6 percent of the votes each. The hard-right Brothers of Italy, who also oppose the euro and permissive immigration policies, and the leftist Tsipras List were struggling with the 4-percent target.

Around half of voters expected to support eurosceptic parties

Counting the M5S, Forza Italia, the Northern League and Brothers of Italy, about half of voters were predicted to support eurosceptic parties – backing results from a recent Pew Research survey which detected a major rise in anti-EU feelings among Italians, bucking trends from other member states.

Italy will be the last EU nation to close its polling stations, at 11 pm Sunday. Voting will start that day at 7 am, also for local elections in over 4,000 municipalities and in two regions, Piedmont in the north-west and Abruzzo in the centre. Expectations are for a record-low turnout, down from 66.5 percent in 2009.

If it pulls off a surprise win, the M5S has said it will call for the resignations of Renzi and President Giorgio Napolitano, followed by fresh elections. The prime minister has ruled out bowing out if defeated, but losing the battle with Grillo will make it much harder for him to press on with his reforms, for whose approval he partly relies on support from Berlusconi.