With that in mind, Martin Schulz told a party congress that he wants the European Union to agree to a new constitutional treaty which creates a federal Europe, which can act together in policy in areas including domestic and foreign security, tax and monetary affairs and asylum and worldwide development. But President Frank-Walter Steinmeier made clear he doesn't want a new election and Schulz has reversed course. "What is important is what we can implement".
Germany is now in the midst of major coalition talks after Merkel's centre-right CDU-CSU bloc failed to agree with the Greens and FDP on forming a new government. A similar call surfaced in a European Commission reform agenda on Wednesday.
Once drafted, it would "be presented to the member states, and those who are against it will simply leave the EU", he said, adding that Poland was already systematically undermining European values and Hungary was increasingly isolating itself.
The Social Democrats have been part of Germany's government for 15 of the past 19 years - first leading a center-left government under Chancellor Gerhard Schroeder from 1998 to 2005, then twice governing in a "grand coalition" under Merkel, from 2005 to 2009 and again from 2013 until now.
In a motion for the congress, the youth wing said the SPD had a "historical responsibility" not to enter government since the far-right Alternative for Germany (AfD) party, which came third in September's election, would then become the official opposition.
Germany, Europe's political and economic powerhouse, has been struggling to build a new government since a September 24 national election in which Merkel's conservative bloc and the SPD both lost support, while the anti-immigrant AfD party surged into parliament, complicating the potential coalition combinations.