The CDU wants to expel the head of the arch-conservative Values Union, Max Otte, from the party because of his planned candidacy for the office of Federal President at the suggestion of the AfD.
The federal executive decided on Tuesday to exclude Otte from the party with immediate effect until further notice.
AfD co-chief Jörg Meuthen had criticized the nomination of the CDU politician Max Otte by his party on Tuesday as unwise.
"I think Max Otte's nomination is wrong in terms of content and strategically unwise," Meuthen told the ARD capital studio on Tuesday.
But he wanted to respect the committee majority of his party.
"The advocates think they can play a trick by nominating the CDU," Meuthen continued.
"In fact, they're more likely to play a trick on the AfD.
With his positions, Max Otte is by no means in the middle of the AfD.” The decision on the candidate is also unimportant, since Otte as an AfD candidate will certainly not move into Bellevue Castle anyway.
The three traffic light parties SPD, Greens and FDP as well as CDU and CSU have meanwhile jointly proposed Frank-Walter Steinmeier for re-election as Federal President.
Her letter to Bundestag President Bärbel Bas (SPD) was signed by the seven party leaders and the heads of their parliamentary groups.
It is available to the German Press Agency in Berlin on Tuesday.
The election by the Federal Assembly will take place on February 13.
Steinmeier's re-election is considered certain.