STRONG FEELING
Highlighting the strength of feeling, two regional party branches have already signalled their opposition to the deal - Saxony Anhalt and Berlin.
"A renewed grand coalition cannot be the result of talks. We reject the start of coalition negotiations with the conservatives," said the motion by Berlin's SPD chief Michael Mueller which was passed.
It singled out unsatisfactory proposals on home building, rents and migration and integration and expressed great disappointment over the absence of plans for a shakeup of the health system.
The SPD's youth wing, Jusos, opposes the deal and its head, Kevin Kuehnert, is undertaking his own "NoGroKo Tour", referring to the faction's opposition to a grand coalition.
However, it is difficult to predict the outcome of Sunday's vote as the regional results are not binding. At the Bonn congress 600 delegates are free to vote how they wish.
Both the states that have rejected the agreement so far are relatively small. Schulz is trying to woo delegates in the biggest state, North Rhine-Westphalia, which has more than one quarter of the votes, in a series of events this week.
Trade unions, some other localities and the state of Brandenburg, have already said they back the deal.
Some leading SPD members argue Sunday's vote is only on the blueprint for a final deal and details can still be negotiated. After any final coalition deal, the SPD's 443,000 members will be balloted.
Some conservatives have expressed confidence that the SPD will back the blueprint. "I can only recommend moving at top speed," said Bavarian conservative Alexander Dobrindt.
"I look forward to starting coalition negotiations on Monday," he said, adding his only concern was the "masochistic way" the SPD had of talking down its successes.
