A new poll from German broadcaster ARD showed Friday that approval rating for Steinbrück, the top candidate for the center-left Social Democrats (SPD) to run against Chancellor Angela Merkel in the September national election, has dropped 12 points in the last month to 36 percent.

Steinbrück came under fire in December, when he said that German chancellors, who earn more than 200,000 euros ($260,000) annually, are underpaid. The comments followed unpopular revelations that he had earned 1.25 million euros in after-dinner speaking fees over the past three years.

The sudden drop means Steinbrück now sits 11th in a ranking of Germany's top politicians. His competitor in the fall, Merkel, leads the list with an approval rating of 65 percent, up five points from last month.

In addition, 26 percent of SPD supporters are in favor of the dropping Steinbrück for another candidate, while 28 percent believe he is doing more harm than good for the party.

Winning Lower Saxony

As Steinbrück falters, so do his party's hopes of unseating the current coalition between Merkel's conservative Christian Democrats (CDU) and the market-oriented Free Democrats (FDP) in Lower Saxony on January 20.

"It's a disaster for Steinbrück," said Jörg Schöneborn, editor-in-chief of ARD's regional network WDR, which publishes the monthly DeustchlandTrend survey. "Ten days before the Lower Saxony election Steinbrück has crash-landed in the poll."

The CDU-FDP majority coalition the two parties hold at the national level is mirrored in the Lower Saxony parliament, and the bellwether state is seen as an important test for the SPD's chances of defeating Merkel this September.

The ARD poll shows the SPD down one point to 33 percent in Lower Saxony and the Greens steady at 13 percent. Meanwhile, the CDU remain at 40 percent while the FDP rose one point to 5 percent, meaning the SPD and Greens hold just a one point lead over the CDU and FDP.

What was once seen as a sure victory in the northwestern state is now uncertain, with the SPD and Greens having lost their 13-point lead over the CDU-FDP partnership they held just six months ago.

Greens reaffirm SPD support

The SPD's decline, combined with the FDP's recent poll struggles, had sparked rumors that the Greens might consider the previously unthinkable and team up with the CDU for the national elections.

The Greens' candidate for chancellor, Katrin Göring Eckhardt, said on Friday, however, that her party still wants to form a coalition with the SPD.

"We can do it together with the SPD," she said.

SPD parliamentary leader Thomas Oppermann also had a positive outlook, saying, "The poll numbers will improve."

dr/mkg (Reuters, dpa)