"Angela Merkel is loved because she gets a women's bonus," Steinbrück told the Frankfurter Allgemeine Sonntagszeitung newspaper.
The statement was part of a slightly clumsy attempt to praise his election opponent, during which he said that female voters in particular admired Merkel's career trajectory.
He said the chancellor had "asserted herself in a men's world, seems very unpretentious and presents herself very modestly," which he said were all qualities that those who traditionally voted for his Social Democratic Party valued too.
"But that doesn't mean that I'm seen as the 'God help us' candidate," he added.
Steinbrück also said that he did not intend to adapt his own presentation style in the upcoming election campaign to counteract Merkel's "advantages."
"That would just be exposed as play-acting anyway," he said, before arguing that elections weren't won by popularity in any case. Steinbrück pointed out that, as state premier of North Rhine-Westphalia in 2005, he had been ahead of his election opponent Jürgen Rüttgers in the popularity polls, but had still lost the election.
The SPD candidate's faux pas comes close on the heels of Saturday's complaint that the German chancellor is paid too little for the amount of responsibility he or she has. "Almost every bank director in North Rhine-Westphalia earns more than the chancellor," he told the FAS.
The statement was a reaction to the recent scrutiny of his own income, and that of politicians in general, but it still caused consternation in his own party.
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"My impression is that the politicians in Germany get paid appropriately," former SPD Chancellor Gerhard Schröder told the Bild am Sonntag newspaper. "I managed to live on it anyway."