ROSARIO SCAVO remembers when 80% of the inhabitants of Borgo Vittoria worked directly or indirectly for the Fiat car company. “It was a city within the city,” he says of the firm, to which he gave 33 years of his life. In those days, it went without saying that this working-class district of Turin, where the gleaming Alps are obscured by dismal apartment blocks, voted for the left. Once it was the Socialists or Communists, more recently the Democratic Party (PD) of Prime Minister Matteo Renzi.

Much of Fiat’s production has since left Italy for cheaper locations. Today, Borgo Vittoria is a lifeless place. A jeweller’s shop bears the melancholy sign “I Buy Gold”. (Not much though, says an assistant: “Those who wanted to sell have already sold.”) As for Mr Scavo, the energetic 62-year-old has already been a pensioner for five years. He gives €300 a month to his university-educated daughter, who has been unable to find any job better than part-time health and social work.

Such grim economic prospects are one reason why, at local elections last month, the Torinese ended 23 years of centre-left government and chucked out their PD mayor, Piero Fassino. Mr Fassino had carried on his predecessors’ project of developing Turin as a tourism destination, but little of that money reached the city’s fringes. In the run-off election, most voters in Borgo Vittoria backed Mr Fassino’s rival, Chiara Appendino (pictured), of the upstart Five Star Movement (M5S). With M5S riding high in the polls (see chart), the PD is growing worried that what happened in Turin could happen in the rest of Italy, too.

Ms Appendino is a 32-year-old graduate of Milan’s Bocconi University, the business school of the northern Italian bourgeoisie. That makes her an odd champion for working-class frustration. But M5S, which was launched in 2009 as an internet-based political insurgency by Beppe Grillo, a comedian, has much to offer such voters. It demands a referendum on membership of the euro, which it blames for Italy’s economic ills. It promises a minimum income for all citizens, whether they work or not. Its candidates hammer relentlessly on the theme of onestà (honesty), a powerful rallying cry in Italy’s dirty political culture. And it has tried to engage disaffected voters by soliciting their ideas. Ms Appendino ran on a platform of 16 planks developed in concert with open-access citizens’ groups. But M5S’s biggest advantage is its ability to appeal to the right as well as the left. Ms Appendino beat Mr Fassino in Turin’s run-off by winning over the voters who had backed right-wing parties in the opening round. In the European Parliament, M5S’s deputies sit with those of the UK Independence Party and Germany’s anti-immigrant Alternativ für Deutschland. M5S’s Eurosceptic tendencies and Mr Grillo’s hostility to immigration appeal to many on the right. This makes the party highly effective in two-round elections. Thanks to an electoral law passed on Mr Renzi’s watch, Italy now has a two-round system not just at local, but at national level. The prime minister is focused on winning a referendum this autumn to alter the constitution so that the next government has a free hand for its entire term. If he loses, he says he will resign, pitching Italy into a government crisis. But for his party an even greater danger is that he could win the referendum—and then lose to M5S in the next election.

Heads we win, tails we win the run-off

M5S is woefully unprepared to govern. Its left- and right-wing impulses are in tension, but, says Marco Ricolfi, a social scientist at the University of Turin, the left-wing side predominates. Last year Mr Grillo tried to get his MPs to vote against decriminalising illegal immigration; he was thwarted by a grassroots mutiny. In Turin, the party is aligned with the sometimes violent resistance by environmentalists to a high-speed rail link through the Alps to France. Ms Appendino’s governing programme vows to promote veganism. The right-wing voters who back it as a protest may not like such policies if it wins.

Worse, the movement’s efforts to solicit citizen input, however laudable, have left its platform a hotchpotch of ingenuousness, cynicism and ambiguity. Its foreign policies are suffused with anti-Americanism. One of its leading members wants to involve leftist Latin American governments in Middle East peace talks. Another returned from Russia to declare that Vladimir Putin should be considered an ally and sanctions should be dropped, since they hurt Italy’s food and furniture exports. On economics, M5S’s main policy is to demand a referendum on the euro. This may be unconstitutional; in any case, M5S will not say whether it wants out or in.

Coherent or not, these policies are popular. An average of recent polls puts the movement less than a percentage point behind the PD. In a run-off between the two, polls find, M5S would win. Italy may well end up granting its government more power, only to elect a party that has no idea how to use it.