Rome: Prime Minister Silvio Berlusconi faced the prospect of a fresh humiliation on Monday following local election defeats, as Italians flocked to the polls to vote in opposition-backed referendums.
Although the government had urged its supporters to stay away, turnout was already at 41 percent late Sunday and voting continues on Monday, suggesting the 50 percent needed for the polls to have legal validity was within reach.
Many of those who have turned out to vote are opposition supporters.
It is widely assumed that referendum questions opposing a return to nuclear power and in favour of revoking a law that gives Berlusconi a form of legal immunity will be approved.
The success of the vote is therefore likely to hinge on the turnout and after Sunday, opposition parties backing the vote were optimistic.
"It`s like the ascension of K2, but I already see the summit," said Antonio di Pietro, the leader of the opposition Italy for Values party.
"We can get there together."
The main opposition Democratic Party also felt that victory was within reach.
"Turnout is high and the quorum is now very close," said a spokesman.
The nuclear referendum would put a definitive stop to government plans to restart Italy`s atomic energy programme by 2014, plans that are already under a temporary moratorium following the Fukushima disaster in Japan.
Voters could also quash a law, approved last year, that allows Berlusconi to skip court appearances because of official obligations.
The Prime Minister, 74, is a defendant in three trials involving allegations of bribery, fraud and paying for sex with a 17-year-old girl.
A Constitutional Court ruling has already curbed much of Berlusconi`s legal protection but the "legitimate impediment" law is still officially in place.
"If we manage to meet the quorum on legitimate impediment it will show that people have turned against the Berlusconi system," Margherita Lodoli, 28, a charity worker in Rome, said after casting her ballots.
"Unfortunately he`ll carry on, he always does, but it will prepare the ground for the next election."
Commentators said the success of the referendums would force a fundamental rethink within Berlusconi`s ruling coalition.
"It`s clear that a wave of `yes` votes will give a shock -- maybe a final one -- to his premiership and then also to the leadership of the PDL," the ruling People of Freedom party, business daily Il Sole 24 Ore said.
The leftist La Repubblica daily said Berlusconi was unlikely to resign if the referendums went against him.
But it added that they could trigger an "implosion" of the People of Freedom and its coalition partner, the Northern League.
There is already infighting within Berlusconi`s party following its defeat in Mayoral Elections in Milan and Naples last month. Many supporters complain that the Prime Minister has lost his campaigning touch.
Il Giornale, a newspaper owned by the Berlusconi family, however warned against over-interpreting the result of the referendums.
"Attributing to the referendums a value that goes beyond what the questions being asked are is an abuse, it`s a dirty game," the newspaper added.
The nuclear issue has been at the centre of heated debates in recent weeks.
Italy abandoned atomic energy with a referendum in 1987 after the Chernobyl disaster, but Berlusconi has made its re-introduction a major policy goal.
His government argues that it would slash electricity bills, reduce Italy`s energy dependency and be better for the environment.
Opinion polls however suggest that nuclear power remains deeply unpopular.
Daniel Cohn-Bendit, leader of the Greens in the European Parliament, has said that a vote against nuclear power in Italy "could open a serious phase of reflection in other member states" of the European Union.
Referendum supporters have stepped up a "get out and vote" campaign in recent weeks, backing up conventional rallies with more unusual tactics.
Beach resorts in the region around the southern city of Naples are offering rental of two deckchairs for the price of one for people who have voted.
Voters are also being offered discounts in bars and restaurants across Italy along with free massages, yoga classes and even concert tickets.
Polling stations are set to re-open at 7:00 am (0500 GMT) on Monday and close at 3:00 pm, with the final result expected later the same day.