The Social Democrats last week reached a coalition government deal with Merkel's bloc that is widely viewed as favorable to the party. The agreement puts the Social Democrats in charge of the powerful Finance Ministry and the Foreign and Labor Ministries, as well as three other ministries it already held.
But it needs approval from the party's 460,000 members and faces some stiff resistance. The party's youth wing is pushing the Social Democrats to go into opposition, and leadership questions mired its top officials.
Seeking to end the infighting, chairman Martin Schulz said Tuesday that he was resigning effective immediately.
The development followed Schulz's announcement Friday that he was abandoning plans to become foreign minister in the new government. His plans to take the ministry had become a major distraction because after September's election he had explicitly ruled out entering Merkel's next Cabinet.
Schulz's other announcement Friday - that Andrea Nahles, the party's parliamentary leader, would take over as the Social Democrats' chairwoman - also gave rise to a chorus of concerns. Protocol would have dictated that a deputy leader step in as interim chairman.
The party leadership reversed course Tuesday and said they were nominating Nahles to run for election as chairwoman at a special party congress on April 22. In the meantime, deputy party leader and Hamburg Mayor Olaf Scholz would take over as interim leader, they said.
"With my resignation from office and decision not to participate in the government, I want to bring the personnel debate in the SPD to an end so that the members can really concentrate on what is in the coalition agreement," Schulz told reporters.
He used the opportunity to lobby for members to sign off on the agreement, saying it was "70 percent" Social Democratic policy and could be used as a springboard to push more of its issues.
"The SPD can build on it if the membership of the party gives us the mandate to enter government," he said. "This is a good coalition deal."
The vote's outcome is expected in early March. If party members reject the agreement, the new coalition government can't be formed. That would leave only an unprecedented minority government under Merkel or a new election as options.
Scholz and Nahles thanked Schulz for his leadership of the party. They said they would now focus on pushing for passage of the coalition agreement.
Scholz is widely expected to become finance minister and vice chancellor in the new government if the coalition agreement is approved.
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