After Britain, Italians go for referendum; voting begins today

The referendum will decide if Italy should amend its constitution; a "no" vote can lead to a regime change

Italians are due to vote on Sunday in a referendum on whether or not the country should amend its 1948 constitution, the media reported.

The referendum, which is being closely watched for further signs of anti-establishment sentiment in Europe and called by Italian Prime Minister Matteo Renzi, is on plans to streamline parliament but is expected to be used by many as a chance to register discontent, BBC reported.

Renzi, 41, wants to defang the upper house of Parliament, the Senate, by cutting its numbers from 315 to 100, thus reducing its powers dramatically, CNN reported.

Populist parties have campaigned for a "no" vote while Renzi has said that he will resign if he loses. Opinion polls suggest he faces defeat.

A "no" vote for Renzi would follow Britain's vote in June to leave the European Union (EU), as well as the rise of the anti-immigrant Front National in France and populist parties elsewhere, along with Donald Trump's unexpected victory in the US presidential election in November.

The "no" campaign in Italy has been spearheaded by the the anti-establishment Five Star Movement, led by comedian-turned-politician Beppe Grillo.

Grillo, much like Trump, has capitalised on widespread disaffection with the status quo. His movement, founded in 2009, now appears to garner almost as much support as Renzi's centre-left Partito Democratico.

Observers fear if Grillo comes to power in an early election, he would call a referendum to scrap the euro, go back to the Italian lira, and perhaps even follow Britain out of the EU.

Opponents say reducing the power of the Senate would concentrate too much power in the Prime Minister's hands.

Some 50 million Italians have the right to vote in the referendum.

An opinion poll in November gave the "no" vote a lead of at least five percentage points. But many Italians are thought to be still undecided.

If Renzi loses, it is still not entirely certain that he would be out of power.

Italian President Sergio Mattarella could ask him to form a new government or appoint a technocratic prime minister to serve until elections due in 2018.

Voting begins on Sunday at 7 am and ends at 11 pm with results expected early on Monday.