BERLIN (Reuters) - Germany's liberal Free Democratic Party, a potential kingmaker after September's national election, ruled out joining any coalition that would provide a financial bail-out to another euro zone country without the participation of the International Monetary Fund.
The FDP leader, Christian Lindner, made the comments on Friday after Finance Minister Wolfgang Schaeuble said on Thursday any new aid programme should not include the IMF, leaving it under European auspices .
Accusing Chancellor Angela Merkel's conservatives of making a U-turn on euro zone rescues, Lindner opposed Schaeuble's idea of developing the euro zone's European Stability Mechanism (ESM) rescue fund into a European monetary fund.
"The FDP would not support such a policy," Lindner told reporters. "For us, it's an absolute condition that the independent expertise and the capital of the IMF continue to be an institutional part in future aid packages in Europe."
Lindner said a European version of the IMF would not be politically independent and a minority of stability-oriented euro zone countries, such as Germany, would be outvoted by a majority of fiscally lenient countries.
The business-friendly FDP was the junior partner in Merkel's 2009-13 conservative-led coalition. But it crashed out of parliament after failing to clear the 5 percent threshold to win seats in the current lower house Bundestag.
Opinion polls suggest six party groups, including the FDP, will enter parliament after the Sept. 24 election, up from four now. Neither Merkel's conservatives nor the SPD would be able to govern alone, opening the way for talks with smaller parties in their efforts to forge a stable coalition government.
Reporting by Michael Nienaber, editing by Larry King