|Opinion polls ahead of the vote show the Social Democrats in the lead [Reuters]
Germany's Christian Democrats, the party of Angela Merkel, looks set for defeat in a state election that could deal a blow to the Germa chancellor's leadership of the country's centre-right government.
Exit polls in Baden-Wuerttemberg on Sunday showed the state slipping out of the hands of Merkel's Christian Democrats (CDU) in an election overshadowed by anger at the chancellor's nuclear policy, as well as decisions on Libya and the euro.
"The election day that is making black-yellow tremble," ran a headline in German newspaper Bild am Sonntag, ahead of the poll, referring to the colours of the ruling coalition of Merkel's CDU and the Free Democrats.
Losing Baden-Wuerttemberg, which lies on the French and Swiss borders and is home to car makers Daimler and Porsche, would weaken Merkel's grip on her party and make it even harder for her to pass legislation in the upper house of parliament.
Opinion polls ahead of the vote showed the Social Democrats (SPD) and their likely allies, the fast-growing Greens, with an edge over the coalition.
The opposition could win 48 per cent of the vote, a survey by the independent TNS Emnid institute, released on Friday, showed.
Campaigning in Baden-Wuerttemberg has been dominated by the nuclear catastrophe in Japan.
Merkel had planned to extend the lifetime of Germany's nuclear reactors, four of which are based in Baden-Wuerttemberg, but the disaster in Japan prompted her to suspend this decision for three months.
She also temporarily shut off the seven oldest reactors pending a safety review.
Nick Spicer, Al Jazeera's correspondent, reporting from Stuttgart, said that decision had not played well with voters, most of whom are opposed nuclear power.
"People here didn't like it when she [Merkel] extended the life of those nuclear plants and then she announced, after the Japanese disaster, a re-think, of her policy," he said.
"But most people are seeing that as political opportunism, a ploy to distract voters from her policy which the majority of Germans actually don't support."
In addition, conservative voters are critical of Berlin's abstention from a UN Security Council vote to create a no-fly zone in Libya, a break with Germany's Western allies.
German media has also been critical of Merkel for agreeing at an EU summit on Thursday to commit to a huge new rescue fund for struggling Eurozone economies.
Merkel's future could be clouded if the CDU loses. When Gerhard Schroeder, Merkel's SPD predecessor as chancellor, lost North Rhine-Westphalia in 2005, he called a snap election and lost.