Support for the 153-year-old SPD has fallen from 20.5 percent in September's general election to 15.5 percent, it found, while the AfD climbed from 12.7 to 16 percent. Merkel's conservative CDU/CSU bloc was largely unchanged at 32 percent.
Bild called the latest survey "a bitter blow" for the venerable SPD. "The conservative bloc is currently the only truly mainstream party," said Hermann Binkert, chief of the Insa polling institute. Support for the SPD has plummeted since its leadership reluctantly agreed to form another "grand coalition" with Merkel's conservatives after an inconclusive general election. The vote saw mainstream parties bleed support to the anti-immigration and anti-Islam AfD, which won more than 90 seats in the German Bundestag.