Rome: Italians began voting on Sunday in referendums on plans to return to nuclear power and on a law granting Silvio Berlusconi immunity in what is seen as a vital test for the embattled premier.
The nuclear vote will be an important marker of popular opinion on atomic energy in Europe in the wake of the Fukushima disaster in Japan and after Germany this week passed a bill phasing out nuclear power by 2022.
If turnout is higher than 50 percent, a vote against nuclear power will definitively scrap the government`s plans to re-start Italy`s atomic energy programme by 2014, which have already been put on a temporary moratorium.
Voters could also strip Berlusconi of his legal immunity under a law that was approved by his government soon after his re-election victory in 2008.
The prime minister is a defendant in three ongoing trials, involving allegations of having paid for sex with a 17-year-old girl, bribery and fraud.
A Constitutional Court ruling earlier this year curbed part of the legal protection linked to his duties but the 74-year-old can still invoke immunity.
A strong vote against Berlusconi would add to signs of growing discontent in Italy seen in local elections earlier this month, in which his ruling People of Freedom party lost crucial mayoral contests in Milan and Naples.
Polling stations close at 10:00 pm (2000 GMT) on Sunday and are open again between 7:00 am and 3:00 pm. The result is expected later on Monday.
The nuclear referendum has received the most attention and has Italians most fired up, eclipsing the vote on legal immunity as well as another referendum on the privatisation of water supplies.
Italy abandoned atomic energy with a referendum in 1987 after the Chernobyl crisis but Berlusconi had made its re-introduction a major policy goal.
The government argues that nuclear power would slash electricity bills, reduce Italy`s energy dependency and be better for the environment.
Opinion polls show however that nuclear power remains deeply unpopular.
The leader of the Greens in the European Parliament, Daniel Cohn-Bendit, has called on Italians to vote against nuclear power, saying that a success on this issue would be "an important signal" to the rest of Europe.