A party conference of Social Democrats on Thursday gave the go-ahead for coalition talks with German Chancellor Angela Merkel's conservative bloc CDU/CSU.
A proposal submitted by party executives to enter preliminary coalition talks with Merkel's conservatives was approved by a large majority of the 600 delegates, after eight hours of heated debate at the conference.
SPD leader Martin Schulz told delegates that preliminary talks would be conducted in an "open-ended" way, and would not necessarily mean Social Democrats would become part of a coalition government.
The SPD's youth section "Jusos" voted against entering coalition talks with Merkel's Christian Democrats, arguing that the election result meant voters had rejected the option of another "grand coalition" between the SPD and the CDU/CSU.
The young Social Democrats called for a comprehensive reform within the party.
SPD re-elects Schulz as leader
The SPD's leader Schulz has managed to claim a second term as party leader on Thursday, receiving 81.9 percent of the vote.
The result is down from the 100 percent support he enjoyed in March, when he was elected as the head of Social Democrats.
The former EU Parliament president Schulz was the only candidate for the party leadership.
"I hope that, on the basis of these results, better times will come," he told the party conference.
Talks to begin next week
The Social Democrats and Merkel's CDU/CSU bloc are expected to hold their first meetings next week.
Merkel's CDU/CSU alliance was the largest bloc after federal elections on Sept. 24, but it failed to secure an absolute majority in the parliament.
Her efforts to create a three-way government with the liberal Free Democratic Party (FDP) and the Greens failed after weeks of post-election negotiations.
Merkel stressed last month that Germany needs a stable government and invited Social Democrats for preliminary talks to form a conservative-left coalition government.
Schulz was previously skeptical about another "grand coalition" with the CDU/CSU, but several leading party figures have supported the idea of entering talks with the conservatives.
Both the SPD and CDU/CSU ended up weakened in September's poll, and many Social Democrats blamed their poor showing on the party's participation in the previous coalition.
Although Merkel's bloc is still the biggest group in the parliament, it needs the support of either the SPD -- the second-largest group in the Bundestag -- or two smaller parties to form a government.
