BERLIN (Reuters) - The Greens have grown out of their woolly jumpers and sandals and turned enough fellow Germans on to environmentalism to make the party -- already the world's most successful green movement -- the possible kingmakers in the 2013 elections.
Founded three decades ago by rebels from the 1968 student movement, 'ban-the-bomb' peaceniks, ecologists and feminists, the Greens got their first taste of power from 1998 to 2005 under Gerhard Schroeder's Social Democrats (SPD).
But they have come into their own in the past year. A strong run of local elections gave them a presence in all 16 regional assemblies for the first time as well as their first state premier, Winfried Kretschmann, who ousted Chancellor Angela Merkel's Christian Democrats (CDU) in conservative Baden-Wuerttemberg.
The progressive "greening" of German politics, with even Merkel converted to the anti-nuclear cause after the disaster at Fukushima and now in a hurry to shut down atomic power plants, has given the party broad appeal in the mainstream.
"We have shown that economics and ecology don't contradict each other -- which is a quantitative leap forward," said party co-leader Claudia Roth in an interview.
"People used to say 'we can afford the Greens when times are good, but when it's a matter of jobs of growth, it's not the Greens you need'," said Roth.
The party has climbed to historic highs in opinion polls in the past year of 15-20 percent, from 10.7 percent in the last elections in 2009.
It has now surpassed the current junior coalition partners, the Free Democrats (FDP), to become the third force in a system that has been dominated by the conservatives, now at around 32 percent, and the SPD, who poll as much as 30 percent.
"There is a really good chance they will get back into government at the next elections," said politics professor Simon Green at Aston University in Britain.
Most analysts agree that a "Red-Green" center-left alliance with the SPD is the most likely option for the Greens. But after the SPD spurned them for a coalition in Berlin's state assembly, citing their opposition to a ring-road extension as an excuse for teaming up with the CDU, the Greens are in no mood to be pushed around.
The SPD are still "without a doubt" her party's first choice, Roth told Reuters.
"But they must treat us as equals, not like some (SPD) spin-off. Schroeder used to talk about 'chiefs and Indians' but that's not good enough anymore."
"It's thanks to the gains made by the Greens that we have been able to oust the center-right in recent state elections, not the SPD who have lost ground or stagnated," Trittin said.
Roth and Cem Oezdemir, who share the party leadership, dangle the threat that the Greens could form an alliance with the CDU instead of the SPD.
"There's no red line about talking to the conservatives, but we must remember we still have a lot of differences," said Roth.
The two have differing views on energy, immigration, social policy and even Europe, where part of the center-right has grown euro-skeptic.
Barbara has voted Green since 1983 and said she watched with dismay as the party has lost its focus on ecology and become more "old and boring." She did not want her full name to be used in a country where asking people how much they earn and which way they vote is largely taboo.
A Berliner, Barbara said the coalition with the SPD had already diluted the Greens' identity, and teaming up with Merkel's conservatives would be the last straw.
"It's a question of what is better -- being eaten by a crocodile or by a tiger," she said.
However, as conservative German voters' old animosity to the environmentalists fades, "well-educated, higher-income people -- the upper-middle class -- are moving toward the Greens and forgetting the old ideological barriers between them," said politics professor Gero Neugebauer at Berlin's Free University.
Now renewable energy is creating more jobs than traditional industry in parts of former East Germany, the financial crisis has turned once radical Green ideas like financial transactions taxes mainstream, and the Greens side with the once-demonized International Monetary Fund in some areas of financial policy.
"Ten years ago this would have been unbelievable," reflected Trittin, co-leader of the Greens in the Bundestag.
Aston University's Green, an expert in German politics, sees the mellowing of policy as part of the aging process.
Some radicals who knitted and swore in parliament in the 1980s have moved on, like Joschka Fischer, the Greens foreign minister paint-bombed over military action in Kosovo in 1999, who became an energy industry advisor.
Legendary Greens founder Petra Kelly died in dramatic circumstances in 1992, shot by her partner at the aged of 44.
Of the present leadership, even those considered more left-wing like Trittin and Roth have shifted toward the moderate positions always espoused by "Realos" (as the pragmatists are known) like Kretschmann in Baden-Wuerttemberg.
They are so respectable even the notoriously conservative Pope Benedict singled them out for praise on a recent visit to the Bundestag, 25 years after a fellow German cardinal called the Greens "unelectable" for their progressive gender policies.
This moderation and balance is precisely what makes the new Greens dangerous for the established "Volksparteien" ("people's parties"), a term historically reserved for the CDU/CSU and SPD, but which the highbrow weekly Die Zeit suggested should now be applied to the environmentalist movement as well.
The Greens are also open about their aim of what Oezdemir calls "poaching among the conservatives" for votes after already taking away votes from the FDP, who have been displaced by the Greens in their historic role of champions of civil rights.
"There is an extraordinary likeness between the voters of the FDP and the voters of the Greens," said Aston University's Green.
But if the Greens are the new Liberals, a scruffy young band of newcomers is a flashback to the Greens 30 years ago, were it not for the laptops and the conspicuous lack of female members.
Less than a month after they surprised Berlin by winning 8.9 percent in the state vote, the Pirate Party -- shipmates of the original Swedish party campaigning for internet freedom -- are scoring similar results in nationwide polls, mobilizing hitherto apathetic young voters and poaching from the center left.
Pollsters say young Green voters are especially vulnerable to the Pirates' charms, and veterans like 72-year-old Berlin MP Hans-Christian Stroebele sees shades of the old, provocative Greens in the Pirates' "self-critical and smart" campaign.
"We have to take them very seriously. We must make sure we are not becoming boring and grey," said Roth, a former rock band manager famous for her bright orange hair and fiery speeches.
The Greens must strike a balance between retaining that old "rebel" allure while promoting responsible policies that appeal to the broad middle class if they want to be in the winning coalition in 2013.
"If there was a really fresh and strong alternative, focused on organic food, energy and taking care of the earth, lots of people like me would leave the Greens," said Barbara.
The conservatives for their part are keen to promote the idea that an SPD-Greens alliance will never work.
Merkel herself told a recent conservative rally that the row between the two over the Berlin ring-road proved the Greens "are still a party of nay-sayers and always will be."
Additional reporting by Erik Kirschbaum; Editing by Sonya Hepinstall