The change comes just a month before the country's federal election.
Germany's Social Democratic Party (SPD) has moved ahead of Angela Merkel's Christian Democratic Union (CDU) in the polls for the first time in fifteen years.
The SPD was polling at 23% while the CDU was one point behind at 22%, according to figures released on Tuesday by Forsa.
It is the first time the Social Democrats have led Germany's polls since October 2006, and it comes a little over a month ahead of the German general elections in September.
Meanwhile, the CDU was rated at its lowest level since the polling institute was set up in 1984.
The German Greens are in third place with 18%, ahead of the Freedom Party (FDP) at 12%. The far-right Alternative for Germany (AfD) is predicted to get 10% and the Left (LINKE) 6%.
Chancellor Merkel is due to step down from her role after 16 years in office and four straight national election victories.
Her departure has increased divisions within the CDU and their Bavarian sister party, the Christian Social Union (CSU), while the SPD has made a spectacular comeback in a matter of weeks
The Socialists candidate for chancellor -- Finance Minister and Vice-Chancellor Olaf Scholz -- also has a clear lead over other candidates in personal ratings.
Armin Laschet won the nomination as the candidate of Merkel's conservative bloc in March after a hard-fought battle, but he has faced criticism for his handling of the COVID-19 pandemic in the state of North Rhine-Westphalia.
Laschet also faced backlash after he was seen laughing at a press conference during floods that hit the region last month.
Germany's Health Minister Jens Spahn -- a close ally of Laschet ally -- has ruled out suggestions that the CDU should replace their candidate ahead of the election on September 26.