It is freezing but the main square of this small town at the foot of the Italian Alps is packed: the angry man on stage is Beppe Grillo, whose movement is tipped to makes waves in next week's election.
"They are attacking us, they're terrorised, because we're doing something exceptional. And no-one gets left behind," he roars to teenagers, pensioners and young mothers with toddlers huddling together in the biting wind.
Grillo's Five Star Movement (M5S), which celebrated a surprise triumph in Sicily's regional election last year, has been boosted by fraud scandals on the right and turmoil at Italy's third largest bank which has hurt the left.
Though 80 percent of the movement's members were left-leaning at the start, Grillo's furious diatribes over the channelling of millions of taxpayer euros into corrupt politicians' pockets have won followers from the right as well.
"Here everyone's sick of hearing lies. Politicians only think about getting the job for money and that's it. They don't do anything for the people," said Giorgio Libero, 63, who used to vote for the centre-left Democratic Party (PD).
Libero said it was time for a change from traditional politics and parties -- a sentiment shared by Patrizia Zanotta, a former right-wing voter.
"Italy needs new faces and new proposals. Voting M5S is a vote for revolution and a bid to change italy -- let's hope Italy listens!"
Zanotta, 43, who runs an electronics company, said she was impressed by the movement's proposals to help small businesses squeezed by the financial crisis -- and also liked the hands-on approach of its wild-eyed, outspoken leader.
"Grillo's just like us, he's one of the people, and the only one who is bothering to travel in his camper van to speak directly to Italians."
The former comedian, who launched his Internet-based movement in 2009, says his rivals -- former Communist and PD head Luigi Bersani and Italy's three-time premier Silvio Berlusconi -- have underestimated the power of rallying.
"There's no contact with the people. They have a parallel life, its like they live in a Truman show," Grillo said over breakfast the next morning.
The 64-year-old holds up to three rallies a day but says the energy of the crowds drives him on: a bad bout of indigestion after the Sondrio show sees concerned townsfolk rush to bring him tea and a hot water bottle in his camper van.
Inside, a pair of tatty blue slippers lie next to Grillo's bed, squeezed in alongside a tiny kitchen where his assistants rustle up quick meals with food donated by fans -- a set-up which seems a long cry from Italy's halls of power.
The last opinion polls before the February 24-25 vote gave M5S between 13 and 18 percent and rising, i9n third place behind Berlusconi's People of Freedom party (PDL) and the front-running PD -- but Grillo is convinced the polls are off.
"Yesterday I realised we are actually going to win the election. The movement crosses the board, we've even got Italians living abroad writing and saying they've heard we're making change and want to play a part," he said.
Those wary of Grillo and what they term his "populist" agenda fear that M5S could end up preventing either the left or right from winning a majority, an outcome analysts warn could spook markets and reignite the eurozone crisis.
Others warn the M5S candidates, all newcomers to politics, may not be up to the task -- and complain that the movement still lacks a candidate for premier.
Grillo is not running for the top job himself: no-one with a criminal conviction is allowed to be a M5S candidate and he was found guilty of manslaughter in 1980 for a fatal car accident which killed three people.
But Denis Ferro, a young candidate in Italy's largest region of Lombardy, an election battleground, said the movement "has what it takes to rule. Sure we're a disparate mix, it's tiring sometimes pulling together, but its amazing too."
Over 50 percent of its candidates are female -- "ordinary women, those who work their butts off, not those who get their butts done," Grillo cries to the audience's delight, in a reference to Berlusconi's female lawmakers.
The second rally of the night, held in the town of Lecco on the shores of Lake Como, is introduced by rappers LeGal, girls in their twenties whose song inspired by Grillo -- "Act now! Believe!" -- goes down a storm with the crowd.
Idealism seems to drive many M5S proposals, from free Internet for everyone and electronic tablets for all school children, to launching a green economy, reducing the working week to 20 hours and revolutionising health care.
"They are just good sense proposals, things you can't say no to," said Vito Crimi, 40, a candidate for parliament, who says the movement's aim is to swap the PIL (Gross Domestic Product) with the BIL -- "Gross Domestic Happiness."
Happiness which for M5S does not rely on fat salaries: the movement has refused to take public financing and parliamentarians in Sicily put 70 percent of their salary into a fund for micro-credit schemes for small companies.
"It's a sacrifice, you need passion for the movement to do it. But it's a lifestyle choice for whoever votes M5S -- you have to participate actively in politics, change your habits: eat, travel, shop in a certain way," Grillo said.
And participate they do: "A fan paid for our petrol the other day and another washed our clothes, it was a God-send," said Salvatore Mandara, who travels in the camper van and films the rallies in streaming for the M5S blog.
"I hope we meet another supporter willing to lend us their washing-machine soon. The show goes on, and I'm running out of clean pants," he said.