Italians have voted to ban nuclear energy for decades in a referendum that was strongly influenced by Japan’s disaster.
Official figures showed almost 95 per cent of votes cast were in favour of blocking a nuclear power revival in earthquake-prone Italy.
Turnout ran at about 57 per cent, according to the Interior Ministry, well above the 50 per cent quorum needed to validate four referendums, including the one on nuclear power.
The referendum abrogates a law passed last year restarting Italy’s nuclear programme, which had previously been halted in 1987 by another referendum following the Chernobyl disaster.
The government, conscious of the backlash from Fukushima, had recently suspended the nuclear programme in an attempt to undermine the referendum. But the vote was seen as ending any prospect of atomic energy in the country in the foreseeable future.
It extended the global impact of the Fukushima disaster after Japan was hit by a massive earthquake and tsunami in March. Germany shut down its seven oldest plants after the disaster and decided last month to close all its reactors by 2022, in a major policy reversal by Chancellor Angela Merkel.
Polls show most Italians, like Germans, are against nuclear energy, an emotion increased by Fukushima in a country which is prone to frequent earthquakes.
Berlusconi is a strong supporter of nuclear power.
His centre-right government had argued atomic electricity generation was essential for energy security in Italy, which imports almost all its power and has some of the highest prices in Europe - partly because of the lack of any nuclear plants.
But Fukushima, combined with a strong effort by the centre-left opposition to get out the vote as a political slap in the face to the prime minister, made selling such plans an uphill battle.
Rome resident Flavio Rellandini said after the vote: “I am really happy. I mean twenty years ago we said the same thing against nuclear power. I just don't understand why they spent all this money to reconfirm this ... We do not want nuclear plants.”
Berlusconi said on Monday, before the referendum result was announced, “We must probably say goodbye to the possibility of nuclear power stations and we must strongly commit ourselves to renewable energy”.
Shares of Italian renewable energy companies rose after his comments, made at a news conference.
Italy, which imports nuclear-generated power from France, gets more than 50 per cent of its electricity from gas, most of which is imported.
The nuclear vote was one of four successful referendums that are a further setback to Berlusconi, already severely weakened by local elections in May, when centre-right candidates suffered humiliating defeats, including in his powerbase of Milan.
Analysts say his second political miscalculation in a few weeks - he urged Italians not to vote in the referendums - would increase pressure on his coalition partners the Northern League to pull out the rug from under Berlusconi’s government before scheduled elections in 2013.
The other referendums were on water privatisation and trial immunity for government ministers - the latter condemned by Berlusconi’s opponents as part of a strategy to get him off the hook in four concurrent trials for fraud, corruption and paying for sex with a teenage nightclub dancer.