By Crispian Balmer
ROME (Reuters) - Prime Minister Matteo Renzi launched his campaign on Saturday to win an October referendum on constitutional reform, staking his political future on an attempt to finally give Italy stable governments.
Recent opinion polls suggest the electorate will reject his proposal to streamline the parliamentary system and strip Italy's regions of some of their decision-making powers.
The 41-year-old prime minister has said he will stand down if he loses, a gamble that could usher in a new era of political chaos and revive market turbulence in the euro zone's third-largest economy.
"We want to make clear that this reform is not just about one person, rather it is a reform that will give Italy a bit of hope for the future," Renzi said in a speech to supporters in the northern city of Bergamo.
"Do you want Italy to carry on as it is now, or do you want to give it a future?"
The reform, which was approved by parliament last month after almost two years of fierce debate, effectively abolishes the upper house Senate as an elected chamber and sharply restricts its ability to veto legislation.
Under the current system, the upper and lower houses of parliament have equal powers and critics say this is one of the reasons why Italy has had 63 governments since World War Two, none of them strong enough to survive a full five-year term.
Opponents say the proposed change would strip away democratic checks and balances that were put in place after World War Two to prevent the rise of another political strongman like the Fascist leader Benito Mussolini.
All the main opposition parties are set to campaign for a 'No' vote. "Dear Renzi, you will be unemployed come October," wrote Renato Brunetta, parliamentary head of the once-dominant Forza Italia (Go Italy!) party, on his Facebook page.
Italy has one of the biggest public debt burdens in Europe, at 133 percent of gross domestic product, and renewed political turmoil could reignite investor doubts about its sustainability, which in turn could raise new doubts about the euro zone.
"Italy's political risk right now does not appear on the radar of markets. The story may change over the next months," analysts at Deutsche Bank said in a note to clients last week.
"The October referendum on the Senate reform is crucial."
Opinion polls in April suggested Renzi would win a clear majority, but a survey carried out this month for RAI state television said 54 percent of people planned to vote 'no'.
If Renzi loses and sticks to his pledge to quit, Italy will be in political limbo. A recent electoral reform was related only to the lower house, in the expectation that the Senate would be removed from the political equation.
That would make a swift general election extremely hard to stage and mean that a new government would probably have to take office to enact yet another overhaul of the voting system.
(Reporting by Crispian Balmer; Editing by Ruth Pitchford)