Rebels from German Chancellor Angela Merkel's coalition partners, the Free Democrats, have collected enough signatures to force a party vote on the EU's permanent bailout fund, they announced Tuesday.

FDP member Frank Schaeffler, one of the most prominent rebels, said on his website that 3,650 signatures had been gathered, or 350 more than necessary to force a party vote on an issue.

Contrary to the pro-business FDP party's leadership, the rebels want a vote on Germany's participation in the European Stability Mechanism, the EU's permanent bailout fund supposed to be in place by 2013.

The motion will be handed to FDP General Secretary Christian Lindner on Monday, Schaeffler said.

"The FDP is the only party in Germany which is allowing its members to decide about the right way out of the debt crisis," he added.

Press reports said the vote could be held by December, adding the party's leadership was expected to submit a counter-proposal in the coming weeks in a bid to block the rebels.

The ESM is due to replace the European Financial Stability Facility (EFSF), which was set up after a first Greek bailout in May 2010 in an effort to stop the eurozone debt crisis from spreading.

On Thursday, German lawmakers voted overwhelmingly to expand the 440-billion-euro ($599 billion) EFSF despite fears of a major backbench rebellion.