Chancellor Angela Merkel's conservative party slipped behind the environmentalist Greens to third place in a state election Sunday, its worst result in Bremen in over 50 years, exit polls showed.

The governing Social Democrats in northern Bremen state extended their lead from 36.7 percent to 38.8 percent of the vote, and their junior partner, the Greens, surged by almost 6 percent to 22 percent, according to calculations based on partial results.

Merkel's Christian Democrats lost about 6 percent, getting only 20 percent of the vote for the state legislature, the party's worst result there since 1959.

The Greens' surge, if confirmed by final results, would also mark the first time in decades that the conservative Christian Democrats were reduced to being the third-strongest party behind the Social Democrats and the Greens in German state or federal elections.

While the Greens' victory in the smallest of Germany's 16 states won't directly affect the chancellor's hold on the federal government, it's another symbolic blow to Merkel's party.

In Baden-Wuerttemberg's state election in March, the Christian Democrats were voted out of the power for the first time in five decades. The anti-nuclear Greens — riding on a wave of broad support in the wake of Japan's Fukushima nuclear plant disaster — became the strongest party there, eventually entitling them to Germany's first Green governor.

Merkel's junior partner in the federal government, the pro-business Free Democrats, won only 2.5 percent of the vote in Bremen, according to the partial results presented by state election commissioner Juergen Wayand.

The Free Democrats thereby failed to re-enter the state parliament, as the minimum threshold is five percent.

The Left party won 6.4 percent of the Bremen vote, down from over 8 percent in 2007, the poll said.

The Greens' rise was also echoed in a new national poll, that saw their support at 23 percent, closely trailing the Social Democrats' 26 percent.

The poll commissioned by public broadcaster ARD and released on Sunday showed Merkel's Christian Democrats at 33 percent, but its coalition partner, the Free Democrats, down to 4 percent.

Merkel's conservatives won Germany's last general election in 2009 with 33.8 percent and joined forces with the liberals, who had then secured 14.6 percent of the vote

About 1,000 people were surveyed for the poll that had a margin of error of up to 3.1 percent.

Sunday's vote in Bremen marked the first time in Germany's history that people between 16 and 18 years old were allowed to vote for their state legislature. Despite that effort to boost the vote, ARD estimated a turnout of only 54 percent, down from 57 percent four years earlier.