Frauke Petry, the co-chair of the far-right Alternative for Germany (AfD), has announced her departure from the party, just two days after elections that saw it become Germany's third-strongest force in parliament.
"It's clear that this step will be taken," Petry said in Dresden, without specifying when she would leave the party.
Petry was sidelined as the AfD's top candidate in the election by Alexander Gauland and Alice Weidel earlier this year in what has reportedly escalated into a row between far-right and more moderate factions.
Petry has criticised the leadership's anti-Islam and anti-migrant rhetoric, saying it alienates mainstream conservative voters and will keep the party in opposition.
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Gauland said on Monday that he could not rule out the possibility of a split.
The AfD won 12.6 per cent of the vote on Sunday, making it the first right-wing party to sit in the Bundestag in 60 years. The result left Chancellor Angela Merkel's conservative political bloc weakened and has complicated coalition talks.
The caucus of more than 90 AfD MPs was holding its first meeting since the election in Berlin on Tuesday.
Petry has won a parliamentary seat through a direct mandate from her constituency in eastern Germany. It's unclear whether she will remain in parliament as an independent or form a new movement.
