The Deutschlandtrend survey, released by public broadcaster ARD on Thursday, showed the SPD hitting a record low of 18 percent of the vote if elections were to be held on Sunday.
In the general election in September, the second strongest party in Germany had hit a historically low result of 20.5 percent.
Support for SPD leader Martin Schulz has also dropped to 25 percent, according to the survey. This is a loss of 5 percentage points since his party announced it would be entering exploratory coalition talks with Chancellor Angela Merkel’s conservatives.
In December, Schulz had pleaded with his party to give him the green light for talks with the Christian Democrats (CDU) and their Bavarian sister party the Christian Social Union (CSU). But following the SPD’s narrow vote to move toward formal negotiations, the leader and his party have seen a decline in popularity.
SPD’s youth wing Jusos have been vocally rejecting any new deal with Merkel. Leader of the Jusos, Kevin Kühnert, has said a re-run of the election would be the best thing for German democracy.
The survey also found that, whereas 52 percent of respondents who identified themselves as SPD members saw a grand coalition government with Merkel’s CDU/CSU Union positively, 46 percent said they viewed it negatively.
71 percent of those surveyed moreover stated that they are losing patience with the length of time it is taking to form a government.
Deutschlandtrend reported that nearly half of respondents - 46 percent - opposed a fourth term for Merkel. Six months ago support for the Chancellor stood at about 70 percent.
But support for Merkel’s conservatives - 33 percent - hasn’t changed since January, according to the survey.
Negotiations between the SPD and Merkel's Union will continue on Friday; it is not yet clear whether talks will be extended beyond their scheduled end on Sunday.
Social Democrat members will have to vote on the coalition agreement with the Union before a new federal government can be formed.