By Erik Kirschbaum
BERLIN (Reuters) - Encouraged by late gains in opinion polls following his strong debate performances against Angela Merkel, German center-left challenger Peer Steinbrueck has sharpened the tone of his attacks on the chancellor in a bid to close the gap.
Steinbrueck's Social Democrats (SPD) still trail the center right by about 14 points ahead of the September 22 election. But with millions of voters still undecided, he used his famously sharp tongue to rip into Merkel on Thursday for usurping SPD ideas.
"Merkel swiped our idea about limiting rent price rises," Steinbrueck told Fritz radio. "But then came the acid test in parliament and she voted against limits on rent increases. You have to watch what she says compared to what she does."
But, aware that he can seem arrogant beside the understated Merkel, Steinbrueck also showed a more human side, admitting in a debate with young voters that he did not have all the answers and giving details about his home life - and even his underwear.
The 66-year-old former finance minister trails far behind Merkel in popularity ratings but believes he and his Greens allies can still win if the SPD can mobilize millions of supporters who stayed at home in the last two elections.
A Forsa poll showed the SPD rising two points to 25 percent while the combined leftist opposition stood just a point behind Merkel's coalition, with 44 percent. Pollsters estimate 20 to 40 percent of Germany's 60 million voters are still undecided.
That means there is still scope for surprises, especially as some smaller parties could thwart Merkel's ambition of ruling for another four years at the head of a center-right coalition.
"The SPD is now succeeding in winning back some of those former supporters who stayed home in the last few elections," said Manfred Guellner, head of the Forsa polling institute. "The unresolved question is: can the SPD keep it up?"
Merkel has warned supporters against complacency, fearing a last-minute dip like the 7-point plunge in conservative support on election day in 2005 versus poll predictions. The center-right has fared worse than expected in the last six elections.
The chancellor has run a cautious campaign based on her own popularity and the theme that Germany is in good economic shape. But she has been eclipsed by Steinbrueck in a TV debate, in parliament and in townhall meetings with voters this week.
Although Merkel enjoys a bonus as the incumbent chancellor, Steinbrueck has been able to score points on the campaign trail with his direct and cerebral style - and newfound humility.
"Steinbrueck has been attacking more and that has livened up the campaign," said Michael Spreng, a prominent media advisor. "But the challenger has to be a lot better than the incumbent when there is no mood for change, not just a bit better."
A drum beat of media criticism of Merkel's "presidential style" may be taking a toll. She was portrayed as "Queen Angela the Great" in a scathing cover portrait in weekly news magazine Der Spiegel, which was titled: "The new smugness of Angela M."
"No other chancellor has amassed as much power in eight years as Merkel but she doesn't use her influence and in her campaign she avoids any and all discussion about the future," Der Spiegel wrote. "Her platform is simple: Merkel."
Steinbrueck, who fancies himself as a straight-talking defender of center-left values, was long seen as arrogant but tried to project a humbler image in two radio and TV debates.
"I don't want to tell you any nonsense when I just don't know the answer," he said at one point, adding at another he wore boxer shorts and once wanted to be a journalist.
One of the most talked-about campaign symbols is a 2,400-square meter photo montage of Merkel's trademark folded hands, facing her office and parliament. Germans have tended to shy away from gigantic political posters since the Nazi era.
Merkel was once asked the meaning of the way she folds her hands in a diamond shape: "Nothing," she replied. Der Spiegel said that made it "the most honest poster of this campaign".
(Writing by Erik Kirschbaum; Additional reporting by Andreas Rinke; Editing by Stephen Brown and Peter Graff)