The upstart Alternative for Germany party advocates an "orderly breakup" of the eurozone. Its chances of getting the 5 percent support needed to win parliamentary seats on Sept. 22 are uncertain though some polls have shown it as high as 4 percent.
If it succeeds, that could complicate Merkel's chances of continuing her center-right coalition—generating speculation about alternative alliances.
Asked in an interview Saturday with the daily Hannoversche Allgemeine Zeitung whether she's ruling out any pact with the new party, Merkel replied: "Yes. This question really does not arise."
Merkel has insisted on tough conditions in exchange for aid to eurozone strugglers.