By Erik Kirschbaum
BERLIN (Reuters) - Germany's center-left opposition is closer to winning a majority in next September's election than Chancellor Angela Merkel's center-right alliance, Social Democrat (SPD) chancellor candidate Peer Steinbrueck said on Friday.
In a fiery speech to SPD leaders, Steinbrueck acknowledged having initial problems in his campaign to oust Merkel's government but pointed out that the SPD and their allies, the Greens, had moved ahead of Merkel's coalition in the polls.
Steinbrueck said that with the SPD and Greens at a combined 44 percent in opinion polls, they are closer to winning power in September than Merkel's Christian Democrats (CDU/CSU) with 39 percent and their Free Democrat (FDP) allies at just 4 percent.
Both sides would be short of a majority because the opposition Left party was projected by the Infratest dimap poll for ARD TV to win 6 percent - meaning the SPD and Greens would need at least 46 percent to win a parliamentary majority.
The center-right is further away from 46 percent. The FDP would fail to win any seats if it stays below the 5 percent threshold needed to return to parliament.
"I want to run a campaign that will clearly spell out the differences between us and them," said Steinbrueck, a former finance minister whose early campaign has been marred by controversy over his lucrative earnings as a public speaker.
"I want you to help me mobilize our side so that our opponents don't put everyone to sleep like last time in 2009 with a campaign to demobilize us," said Steinbrueck.
He was referring to Merkel's soft-style tactics and her conservatives' shift to the political center.
Support for the SPD itself has recently stayed fairly flat but the Greens received a boost after their new leaders made a pitch for conservative voters by projecting a more moderate, sober image. A poll this week gave them 16 percent, the highest level this year, amid talk of them trying to cut a coalition deal with Merkel, not the SPD, next year.
The SPD plunged to a post-World War Two low of 23 percent in 2009, losing nearly half the support - 40.9 percent - they got when they won power with the Greens in 1998. Merkel pushed her conservatives to the center, siphoning away some SPD voters and prompting others to stay home on election day.
"We need to take clear positions and stand up for them. We can't let them take away our issues again because we're closer to winning a majority than they are - even if the FDP manage to get back above the 5 percent hurdle," said Steinbrueck.
"An SPD-Greens government is much more probable at the moment than a CDU/CSU-FDP government," he said, referring to the center-left's small lead in the polls.
Steinbrueck fell well behind Merkel in personal popularity ratings in the last month, losing support with his abrasive style and the row over his well-paid speaking engagements. He spent much of his first month as candidate defending himself for earning 1.25 million euros as an after-dinner speaker in three years - more than many SPD voters earn in a lifetime.
Steinbrueck was once seen as the center-left's best hope of winning back the chancellery they last held under Gerhard Schroeder from 1998 to 2005.
Steinbrueck served as finance minister in an unwieldy, conservative-SPD "grand coalition" under Merkel from 2005 to 2009. Political analysts say such a coalition is the most likely scenario after next year's election too, but Steinbrueck has ruled out serving again under Merkel.
He showed SPD leaders on Friday he was ready for a spirited campaign and poked fun at the fact that, unlike Schroeder, who has been married four times, he has had only one wife.
"If you want to accomplish anything in the SPD it seems you have to have been divorced four times," Steinbrueck joked. "Maybe that's why I'm having so many problems at the moment - I'm still in my first marriage."
(Editing by Gareth Jones and Mark Heinrich)