Germany's Greens pledged to fight a joint battle with the centre-left Social Democrats against conservative Chancellor Angela Merkel in elections five months away as they wrapped up a three-day party congress Sunday.
The Greens, who grew out of the 1970s peace, anti-nuclear and environmental movements, are now the country's third-biggest political force and are hoping to return to national government with the campaign slogan "Germany is renewable."
At their Berlin party congress, the Greens, who score around 15 percent in polls, committed to stick with the Social Democrats as alliance partners despite the weakness of that party's would-be chancellor Peer Steinbrueck, whose campaign has been hobbled by a series of missteps.
The fact that a "red-green" alliance is now trailing Merkel's coalition government in polls has raised talk about a once-taboo idea -- that the Greens could turn to Merkel's conservative Christian Democrats, if both sides want to form a coalition government after the September 22 poll.
But the Green state premier of Baden-Wuerttemberg, Winfried Kretschmann, confidently declared that red-green state governments are "the vanguard" for the next federal government, telling delegates: "We can win these elections because the citizens can trust us."
One of the two top Greens candidates, Katrin Goering-Eckardt, a Christian church leader who like Merkel hails from the former East Germany, told the meeting that the Greens do not represent a narrow interest group but are "the lobby for the real life out there."
The previous day, Sigmar Gabriel became the first Social Democratic Party (SPD) chief to address a Greens meeting, rallying members for a joint fight against Merkel and her eurozone crisis management which Gabriel labelled a "policy that has no tomorrow" .
The second in the Greens duo of top candidates, Juergen Trittin, argued that the party already governs with its partners in states that cover 50 million of Germany's roughly 80 million people, and that it hopes to "convince the other 30 million."
Speaking to the Handelsblatt daily, Trittin quipped that one could now ride a bicycle across much of the country "without the risk of hitting a Christian Democratic state premier along the way."
As the party agreed on its campaign manifesto in Berlin, it pledged to speed up Germany's transition from nuclear power to renewable energies -- a long-time Greens demand adopted by Merkel after the 2011 Fukushima disaster.
The party also demanded a minimum wage of at least 8.50 euros ($11) an hour.
And, in a victory for the party's left wing over conservatives led by Kretschmann, it decided to seek a tax rise for annual income above 80,000 euros to 49 percent, up from 42 percent now, and to tax assets of over one million euros at 1.5 percent.
The party also pledged to fight for a more democratic Europe, and said it would stop German weapons exports to countries with questionable human rights records, citing sales of armoured vehicles to Saudi Arabia and Qatar.