Angela Merkel’s centre-left opponents took tough bargaining positions yesterday for the political poker game that follows her German election victory, with the Social Democrats and Greens feigning no interest in forming a coalition with her.

The conservative Chancellor fell just short of an absolute majority on Sunday, meaning she has to form a government with one of three other parties who made it into Parliament.

With one far-left party out of the question as a partner for her conservatives, that leaves only the Social Democrats (SPD) and Greens. Both began a negotiating process that could last months by swearing they would rather stay in opposition than help Merkel serve a third term.

The SPD remains the most likely partner for Merkel. Even after a second consecutive disastrous election, it is the biggest party after the conservatives and will ask a high price for repeating the “grand coalition” which Merkel led from 2005 to 2009.

Regional SPD leaders, who are influential in a system where power is divided between Berlin and the federal states, want to put any deal to a vote by over 472,000 party members.

“At the end of such a process, our members must have the last word,” said Nils Schmid, SPD leader in Baden-Wuerttemberg state, adding that his followers had “no interest in always saving Frau Merkel’s bacon”.

The SPD leadership meets on Friday to discuss strategies and the membership vote.

Grassroots SPD supporters find the idea of being Merkel’s junior partner again distasteful and it is far from certain whether members would back a grand coalition.

But given that Merkel’s options other than a coalition are an unstable minority government or new elections, political scientist Hans Vorlaender said the likely outcome was “a more Social Democratic” country.

“The advantage is that it would ensure greater political stability and there would be no blockades by the (SPD-dominated) Bundesrat upper house,” said the Dresden University professor.

The Greens are purging their leadership after an election that relegated them to the smallest party in Parliament. Katrin Goering-Eckardt, one of the few Green leaders left standing, said differences with the conservatives were too wide for the two parties to work effectively together in government.