The center-right will take a tough stance against any members who suggest a coalition with the nationalist AfD. The CDU called the AfD a party that "tolerates anti-Semitism and racism" and far-right extremism.
Chancellor Angela Merkel's Christian Democrats (CDU) said Monday that it would become official party policy never to entertain the idea of entering into a governing coalition, or even engage in political cooperation, with the far-right Alternative for Germany (AfD).
CDU General Secretary Paul Ziemak said "anyone in the CDU who is pleading for rapprochement or cooperation with the AfD should know that they are talking about a party that tolerates right-wing extremist thought, anti-Semitism and racism within its own ranks."
"The CDU refuses any coalition or similar form of cooperation with the AfD. Period."
There have been several rumors that the AfD and the CDU might work together in recent years, as a large part of the AfD's voter base are former CDU voters who disagree with Merkel's bringing the party toward the center.
The CDU's statement came one day after Friedrich Merz, Merkel's onetime rival for leadership of the CDU, told the Bild am Sonntag newspaper the CDU was hemorrhaging voters in the more conservative wing of the party, particularly among "police officers and the military."
'The social and the national' remark sparks outrage
Monday marked the second time in four days that Ziemak was prompted to make such a declaration. Last week, he wrote on Twitter that "One more time for everyone taking notes: the CDU strictly rejects any coalition or cooperation with the AfD!!!"
This was a response to an open letter in the Mitteldeutsche Zeitung from two CDU lawmakers in the eastern state of Saxony-Anhalt, where support for the AfD is stronger than in the west.