As delegates trickled in for the second day of their party's conference, they were greeted by a handful of protesters braving the icy cold drizzle: "The SPD is once again hip, it has to stop TTIP", they chanted, as they held out damp leaflets condemning the free-trade agreement between the EU and USA currently under discussion.

Inside, meanwhile, Sigmar Gabriel, party leader, vice-chancellor and economics minister in one, did his best to convince the 600 delegates that the SPD – Chancellor Angela Merkel's junior partners in the grand coalition government - was indeed about to emerge from the shadow of its coalition partners.

"Without the SPD", he called as delegates cheered enthusiastically, "the government would be paralyzed by now", refering to the rift between Merkel's Christian Democrats (CDU) party and its Bavarian sister party the Christian Social Union (CSU), which has emerged increasingly highly critical of her "open-door" refugee policy.

In 2017, when German voters head to the polls again, the SPD would emerge as the winner, Gabriel vowed as delegates cheered: "We want to rule Germany again, and not just as part of a coalition."

Uphill climb

His combative speech comes at a time when polls continue to paint a somewhat different picture: According to pollsters, Forschungsgruppe Wahlen, published on Friday, only 24 percent of voters support the SPD – the lowest level in the last nine months and barely more than in the 2009 elections when support for the party dropped to 23 percent, the SPD's worst in post-war Germany.

Sigmar Gabriel acknowledged the applause after his speech

In his speech Gabriel attacked Merkel and her party for pursuing a "hypocritical double strategy" in the refugee crisis. "You can't expect to be celebrated in the morning for letting one million refugees come to Germany and then, later on in the day, pass laws aimed at treating them worse", Gabriel said, who reiterated the party's call for a European-wide quota system.

Gabriel also attacked Merkel's austerity policies. "I repeatedly warned Angela Merkel not to force austerity on France", he called, veering from his written speech, "I told her it would only boost the National Front", referring to the far-right group which emerged as the largest party in the first round of regional elections last Sunday.

The National Front's success, he warned, came at a time when right-wing populists flourished in countries such as Poland, Finland, Sweden and Germany, where the AfD Party is expected to do well in several state elections next year.

It was up to European Social Democrats, Gabriel thundered, to fight against "these enemies of Europe."

Playing to party left

On Syria, Gabriel promised delegates a vote before any future extension of the mandate of Germany's military currently being deployed to support the anti-IS coalition with reconnaissance jets and a frigate – a mission which was passed by Parliament last week, with 28 SPD MPs voting against the mandate.

When it came to questions of war and peace, "only party members and no one else should have the right to decide the SPD's position", he said.

The re-elected SPD chairman (seated) with other party leaders

After a thundering applause, which went on for several minutes, delegates trickled out for lunch.

Inside, 25-year-old Nicolar Weckwerth from Schleswig-Holstein, sporting a bright-red scarf, told DW he fully supported Sigmar Gabriel. "His speech was very convincing", he said.

Others though, particularly from the party's left, disagreed: Tobias Afsali from the SPD's youth wing took to the stage, accused him of lacking “clear red lines” and selling out to his coalition partners in several important policy areas: "We have to stop being the left wing of the CDU", he called.

Later in the afternoon, after technical problems forced organizers to switch from tablets to paper and pens, 74 percent of the 614 delegates who cast their ballots voted to reelect Sigmar Gabriel as party leader. There were no challengers.

This is considerably lower than the 83.6 percent approval he gained at the conference two years ago.

Sigmar Gabriel did his best to shrug off the results: "Such is life in a democracy", he said, adding that some within his party didn't believe his policies "are left enough."

But, he said, three quarters had voted for him, "and that's why I accept this vote", as delegates clapped and cheered.