Merkel's ally rules out teaming up with challenger

German Chancellor Angela Merkel, center, arrives at the weekly cabinet meeting in Berlin, Wednesday, Sept. 11, 2013. Merkel will run for her third term in the German general elections on Sept. 22. Left are Minister of State at the Foreign Ministry Michael Georg Link, second left Vice Chancellor and Economic Minister Philipp Roesler and right Roland Pofalla, Head of the Federal Chancellery. (AP Photo/Markus Schreiber)

BERLIN (AP) — Chancellor Angela Merkel's junior coalition partners on Thursday formally ruled out teaming up with her center-left rivals, portraying themselves as a bulwark against tax hikes and pooling of European debt as they sought to motivate supporters ahead of Germany's elections.

The pro-market Free Democratic Party joined Merkel's government when her second term began in 2009, a center-right alliance that has at times been bad-tempered. Polls show only a wafer-thin majority for the coalition.

The FDP could conceivably offer center-left challenger Peer Steinbrueck a route to power if they teamed up with him instead. However, its supporters lean to the right and the party — the traditional kingmaker of German politics, though that role has eroded somewhat — has largely allied with Merkel's conservative Christian Democrats since the 1980s.

The FDP has been struggling in polls, which show it around the 5 percent support needed to keep seats in Parliament in the Sept. 22 election. It polled nearly 15 percent four years ago but has taken much of the blame for coalition infighting, particularly over the FDP's never-realized pledges of major tax cuts.

In a statement issued by party leaders at a rally Thursday, it touted its debt-fighting credentials and promises of future tax relief and asserted that any coalition government other than the current one, even if led by Merkel, would lead to tax increases.

The opposition parties "want to raise taxes, push up public spending and debt, create a debt union in Europe and make our country a republic of paternalism and bans," the FDP said.

That, it said, means it's ruling out a coalition with Steinbrueck's Social Democrats and their Green allies, who are more open than Merkel and the FDP to limited pooling of European debt in the continent's crisis.