German Chancellor Angela Merkel will be forced to re-evaluate her election year strategy after a bitter defeat to the centre-left opposition in a cliffhanger state poll.
In one of the tightest state races in recent memory, the Social Democrats and the Greens on Sunday eked out a one-seat majority in Lower Saxony over the incumbent coalition of Merkel's Christian Democrats with the Free Democrats.
After a suspense-packed night with broad implications for the September general election, the centre-left camp said it aimed to use its victory to create fresh momentum in its bid to deprive Merkel of a third four-year term.
"It shows the race until September is far from over," the Social Democrats' challenger to Merkel, Peer Steinbrueck, said.
Merkel, who campaigned hard for state premier David McAllister, a half-Scot seen as a potential successor to her, enjoys a strong lead in national polls due to her defence of German interests in the euro zone crisis.
But pundits said the state win could help shore up the battered campaign of the gaffe-prone Steinbrueck.
After a series of regional poll setbacks, Merkel's Christian Democrats (CDU) were the strongest single party with 36 per cent of the vote. Their state coalition partners for the last decade, the pro-business Free Democrats (FDP), drew nearly 10 per cent - more than doubling many pollsters' forecasts and tallying their best result in Lower Saxony in post-war history.
But their cumulative result fell just short of the Social Democrats (SPD) with around 33 per cent and the Greens' 14 per cent, meaning the opposition can build a governing majority in Germany's fourth most populous state. The centre-left Sueddeutsche Zeitung said the election granted the flailing FDP and the beleaguered Social Democrats a possible new lease of life.