BERLIN (Reuters) - The youth wing of German Chancellor Angela Merkel's conservatives voted on Friday in favor of a members' ballot on who should be the bloc's next chancellor candidate, dealing a setback to front-runner Annegret Kramp-Karrenbauer.
The vote by the Junge Union could force Merkel's Christian Democrats (CDU) to discuss the possibility of such a ballot when they meet at a party congress in November, potentially disrupting Merkel's efforts to stage manage an orderly handover.
Such a debate would be an embarrassment for Kramp-Karrenbauer, who won the CDU party chair last December before committing a series of gaffes that have sapped her popularity and raised questions about her credentials to succeed Merkel.
Junge Union head Tilman Kuban said on Twitter that 61% of the 277 votes collected during a congress in the western city of Saarbruecken were in favor of a ballot on who should lead the conservatives in the next election.
As CDU chairwoman, Kramp-Karrenbauer, who is also defense minister, hoped to be the conservatives' automatic choice to succeed Merkel, who has said she will not seek re-election after this parliamentary term, due to run until autumn 2021.
But Kramp-Karrenbauer's gaffes - including poking fun at trans-gender people in a light-hearted carnival speech - have raised questions about her political instincts and trashed her popularity ratings.
Merkel's conservatives formed a loveless coalition with the center-left Social Democrats (SPD) after an election two years ago in which both parties suffered losses to the far right. The coalition is up for a mid-term review by the end of the year.
If the SPD, who are under pressure from leftists in the party to rebuild in opposition, choose to quit the coalition by the end of year, a snap election could be held.
Polls show the conservatives would come first, with the Greens as the second-biggest party, and the far-right Alternative for Germany (AfD) in third place, followed by the SPD.