Chancellor Angela Merkel's party has suffered a severe defeat in a pivotal German state vote.
The defeat is likely to award her main rivals a major boost in their bid to soften her austerity drive in Europe.
Around 16 months before national elections, the poll in the state of North Rhine-Westphalia, Germany's most populous with 18 million people, is closely watched as a taste of things to come at federal level.
While Germans nationally back Ms Merkel and her tough stance on European belt tightening and debt reduction, voters in NRW handed her conservatives their worst ever result in the western state.
Her Christian Democatic Union (CDU) won just over 26%, according to preliminary results, while the main opposition Social Democrats (SPD) took 39% in NRW, home to the Ruhr industrial heartland.
The result is a further blow to Ms Merkel, a week after her strategy for fighting the eurozone crisis took a hit in Greek and French votes, prompting her to warn against "growth on credit".
It also comes two days before she hosts French president-elect Francois Hollande who campaigned on a pledge to renegotiate the eurozone's fiscal pact for tighter budgetary rigour which Ms Merkel argues is essential to underpin the continent's eventual recovery.
The SPD has echoed calls by Mr Hollande to place more emphasis on growth in the fiscal pact and Ms Merkel, who needs a two-thirds majority in parliament to ratify the fiscal pact, will therefore need opposition support.
