Under the motto “Together. For Germany” the SPD's congress of 600 delegates on Sunday is expected to name Peer Steinbrück, 65, as the party's candidate for chancellor.

In his highly anticipated speech Steinbrück said, "Germany again needs more we and less me."

Steinbrück called for a new social harmony in Germany. "It's about a new balance. It's about the Renaissance of the social market economy. And it's about making the market economy much stronger for the sake of the common good."

SPD party leadership had nominated Steinbrück in September as its lead candidate.

Yet with Chancellor Merkel's popularity high, the center-left SPD has struggled to offer the public a compelling argument to vote her out.

Revelations of Steinbrück's huge earnings outside of politics on the lecture circuit have also put him on the defensive. As a self-assured public speaker with a razor wit Steinbrück earned 1.25 million euros (1.6 million dollars) for fewer than 100 lectures since ending his stint as finance minister in 2009. This revelation has left leftwing critics to question whether he can speak the language of working class voters.

Key planks in the SPD campaign platform, which is not to be finalized until April, are likely to include tax hikes for the rich, more spending on education and increases in minimum wages.

The race is on

Merkel's chief vulnerability ahead of the election is the sagging fortunes of her current small coalition partner, the pro-business Free Democratic Party (FDP).

If the FDP fails, which now appears likely, to win any seats at the September 2012 general election, she would have to turn to either the SPD or the opposition Green Party to form a new government.

A poll this week for public television shows those two opposition groups drawing 30 and 14 percent of support respectively, which is too little to form a coalition of their own to push Merkel out.

The same poll showed one third of Germans expect Germany to be ruled from next autumn by a CDU-SPD "grand" coalition, the same combination that Merkel led during her first 2005-09 chancellorship.

hc/sej (AFP, dapd, dpa)