Wiesbaden, Germany  - After months of political manoeuvring, a German Social Democratic (SPD) leader on Friday unveiled details of her legislative takeover bid in the central state of Hesse.

Andrea Ypsilanti said she would invite legislators to elect her as premier on November 4, leading a minority coalition government with the Greens and counting on the votes of the Left party.

Chancellor Angela Merkel's Christian Democratic Union (CDU) immediately accused Ypsilanti of breaking a pre-election promise not to ally with the Left, which embraces former East German communists and western leftists.

If the incumbent CDU premier in Hesse, Roland Koch, is toppled, it would likely strain Merkel's federal coalition with the SPD, one year before the September 2009 general election in Germany.

In the state capital of Wiesbaden, Ypsilanti unveiled details of a coalition agreement with leaders of the Greens party. They would promote investment in renewable energy and delay the expansion of Frankfurt's airport.

Koch narrowly lost a state legislative election nine months ago. As caretaker premier since, he has sought to weaken the three competing parties which oppose him and has criticized their plans for a loose alliance to vote him out of office.

Ypsilanti, 51, would not be Germany's first woman state premier, but follows in the Social Democratic footsteps of Heide Simonis, who ran the state of Schleswig-Holstein from 1993 till 2005.

She said her government would include 10 Social Democrats and two Greens, including the Greens leader Tarek Al-Wazir as environment minister.

The environmentalists oppose expansion of the airport, which they say already causes too much noise and spoils the landscape. The coalition is to seek a ban on night landings.

In Berlin, CDU general secretary Ronald Pofalla called the new Hesse alliance a "reckless political experiment" based on the SPD "breaking a promise" not to link up with the Left.

The CDU has suggested that the SPD may also seek a federal alliance with the Left, which is anathema to many voters in western Germany. Ypsilanti has also faced opposition to the alliance in her own SPD ranks. (dpa)