The pledge is intended to boost the chances for Ypsilanti to move ahead with her controversial plans to rely on the leftists to become state premier this autumn after an inconclusive election last January.
“The Left's faction clearly has a common position. I assume that we would remain united through 2013,” Willi van Ooyen, the party's state parliamentary floor leader, told daily Die Welt on Tuesday. “We say what we do and do what we say.”
Social Democrats in Hesse said last week they would push for an alliance with The Left and with the Green Party to force out the current caretaker state government led by the conservative incumbent Roland Koch from the Christian Democrats.
Ypsilanti failed to forge a minority government with the Greens in March, after one of her own backbenchers balked at the idea of letting her being elected state premier with the votes from The Left, which has sapped the SPD's support by touting populist socialist policies.