German Chancellor Angela Merkel's most prominent domestic critic in the migrant crisis says he won't "sell the soul" of his conservative party in a dispute over his demand for a cap on the number of refugees that Germany accepts.

Horst Seehofer is Bavaria's governor and the leader of the Christian Social Union, the Bavarian arm of Merkel's Union bloc. Seehofer has long criticized Merkel's welcoming approach to migrants last year and is pressing for an annual refugee cap in Germany of 200,000 — a call Merkel and allies so far have rejected.

A national election is expected next September. Seehofer told Sunday's Bild am Sonntag newspaper that he hopes to resolve the dispute this month — but "I won't give up this core element just so that there is harmony."