GERMANY’S ANTI-NUCLEAR Greens scored a remarkable victory over Chancellor Angela Merkel’s conservative party in a state election that turned into a referendum on nuclear power in the wake of Japan’s Fukushima disaster.

The Greens doubled their voter share in wealthy Baden-Wuerttemberg state and seemed poised to oust Merkel’s Christian Democrats who held power there for almost six decades, according to preliminary results released by the state electoral commission.

The Greens are also set to win their first ever state governorship, Sunday’s results showed.

“This is a day that has strongly changed the political landscape in Germany,” party chairwoman Claudia Roth said in Berlin.

The Greens secured 24.2 per cent of the vote, with the center-left Social Democrats down 2 percentage points at 23.1 per cent. That secures them a narrow lead to form a coalition government with a combined 71 seats in the state legislature, the results showed.

“We have secured what amounts to a historic electoral victory,” the Greens’ local leader Winfried Kretschmann told party members in Stuttgart.

Representatives of all parties said the elections were overshadowed by Japan’s nuclear crisis, turning them into a popular vote on the country’s future use of nuclear power — which a majority of Germans oppose as they view it as inherently dangerous.

Conservative governor Stefan Mappus, who has long been an advocate of nuclear energy, conceded defeat and said his party’s lead in the polls dwindled away in the wake of the disaster at Japan’s Fukushima nuclear facility.

“Voters were touched by the terrible events in Japan, those images still haunt people today,” he said.

Mappus’ Christian Democrats secured 39 percent of the vote or 60 seats in the legislature. Its coalition partner, the pro-business Free Democrats, saw its voter share halved to 5.3 per cent — 7 seats.

The disaster in Japan triggered Merkel’s government last week to order a temporary shutdown of seven of the country’s older reactors, two of them in Baden-Wuerttemberg state, pending thorough safety investigations.

But the chancellor’s abrupt about-face has raised doubts about her credibility in a country that remembers well the 1986 Chernobyl disaster in Ukraine that spewed radiation across Europe.

A centre-left government a decade ago penned a plan to abandon the technology for good by 2021, but Merkel’s government last year amended it to extend the plants’ lifetime by an average of 12 years.

The government has now put that plan on hold, and the opposition wants to abolish the use of nuclear power for good by 2020. Germany currently gets about a quarter of its energy from nuclear power, but plans to eventually replace it with renewable energies.

Merkel’s party has held power in the region around Stuttgart — home to some 11 million people — since 1953 and the ballot was seen as the most important of Germany’s seven state elections this year.

The prosperous southwestern region, home to carmakers Daimler AG, Porsche SE and software house SAP AG, was the only state where the same centre-right coalition that governs Germany as a whole had to face state voters.

The Greens’ success there was also partly explained by its opposition to a disputed railway project in Stuttgart, which the center-right government tried to push through despite widespread protests.

The results in Baden-Wuerttemberg also further weaken Merkel’s coalition’s stance in Germany’s upper house of parliament, which represents the 16 states, increasingly forcing her to seek compromises to get major legislation passed.

Also voting Sunday was Rhineland-Palatinate state, where preliminary official results saw the Social Democrats losing their absolute majority, poised to form a coalition government with the triumphant Greens who more than trebled their vote.

Governor Kurt Beck’s Social Democrats fell 9.9 percentage points to 35.7 per cent, while the Greens rose from 4.6 per cent to 15.4 per cent.

The Christian Democrats are seen gaining 2.5 points to 35.3 per cent. The Free Democrats fell below 5 per cent and thus would no longer be in the state parliament, according to the preliminary results.

- AP