By Alexandra Hudson
BERLIN (Reuters) - Germany's Free Democrats have spent more time in government than any other party since World War Two. Now, Chancellor Angela Merkel's coalition partners are struggling to avoid dropping out of parliament altogether.
With its novice leader under fire, the liberal, pro-business party meets in Stuttgart this weekend to try to stop the rot before a general election that could wipe it out.
If the party, as polls currently indicate, falls short of the 5 percent threshold in the federal vote, it will be ejected from parliament for the first time since its founding in 1948.
Merkel, whose Christian Democrats (CDU) are riding high in national polls at about 40 percent, would then be forced to seek a coalition with the Social Democrats (SPD) or Greens in order to secure a third term.
Much of the FDP's internal strife centers on 39-year-old Vietnamese-born leader Philipp Roesler, whose attempt to inject new dynamism on taking over in May 2011 failed spectacularly.
Within a year, support for the FDP fell to 4 percent from a record 14.6 percent at the 2009 election.
Germans jokingly brand the FDP a party of the affluent, of dentists and tax advisers. But it is the party's inability to appeal to the center, its failure to push through campaign pledges on tax breaks, that have cost it support.
Roesler's predecessor, Foreign Minister Guido Westerwelle, also proved deeply unpopular, not least for his decision to break with traditional allies in refusing to back a U.N. resolution authorizing military action in Libya.
A recent survey by pollster Forsa showed 76 percent of FDP voters would rather see Rainer Bruederle, a 67-year-old FDP veteran and former minister, in charge of the party.
The party's survival may hinge on ditching Roesler, Forsa's head Manfred Guellner said, a step that could come after a state vote in Lower Saxony on January 20 where the FDP could also fail to hit the 5 percent mark.
"The FDP still has a chance to save itself before the election in the autumn, but it depends on whether they replace Roesler," Guellner said.
Lower Saxony is Roesler's home state, making a defeat there especially damning.
The FDP has been in government with either the left or the right for 46 years of the Bundestag's 63-year history, but has had a terrible 2011 and 2012. It was expelled from six of Germany's 16 regional governments, polling a pitiful 1.2 percent in the western state of Saarland last May.
The party did claw back enough support to return to the assemblies in Germany's most populous state, North Rhine-Westphalia, and in Schleswig-Holstein, last year. But that was largely because of popular local candidates who openly shunned Roesler.
High profile liberals have tried to paint over the cracks and seek to credit the party for Germany's robust economic health. But at grass roots level the despondency is intense.
"The mood was bad last year and has only got worse since then," Julien Flaig, an FDP local councillor in Stuttgart, told Reuters. "Roesler has continued to make mistakes, and some within the party fear that there simply isn't enough time to rebuild and find a way back into parliament."
Expulsion from the Bundestag could wipe out state funding and private donations to the party, making a return even harder.
Guellner, the pollster, said there was still a desire in Germany for a liberal party, in particular from the "Mittelstand" of smaller, family-run businesses. In Stuttgart, the party hopes it can finally start the process of winning back those voters.
(Additional reporting by Matthias Sobolewski; Editing by Robin Pomeroy)