This was just reported a few hours ago and I couldn't yet find an English article on it. Once there is I will probably make a post in Cancelled.
In short, Sahra Wagenknecht is a "TERF" (not self-declared but her views mostly align with radical feminism) and I've translated a quote of hers below, but first I will give some context.
She is one of the most important politicians of the German party "The Left", and arguably the most popular one. As the name suggests, the party is the most left-wing of the mainstream parties; it was actually formed by a merger of remnants of the East German communist state party and a few small West German socialist parties.
In April of this year, she published a book that is critical of her party's embrace of identity politics and left liberalism, i.e. neoliberalism with (supposedly) progressive social policies. "The Left" used to get pretty good vote percentages, especially in East Germany, which are still the poorer states of Germany, but over recent years has been losing voters in this specific region and in general, particularly since a right-wing populist party founded in 2013 has become mainstream. Wagenknecht blames the aforementioned focus of her party for the loss in popular support.
Officially, the reason why other members want to forcibly exclude her from the party is that her book is too critical and damaging to the party's image. However, I translated a short quote from the book, and you can judge for yourself if maybe there are other reasons:
Books burned publicly
One need not necessarily think conservatively, talk about problems with immigration, or defend the social survival of one's home region, to become the target of fierce attacks. Even the notion that there are natural differences between women and men, not just social gender roles, can cause a veritable storm of rage, as the author of Harry Potter, Joanne K. Rowling, had to experience. Understanding what's behind the hate campaign requires one to know that left-liberal gender ideology denies the existence of biological sex. By now, Rowling had death wished upon her due to her supposed transphobia, and her most recent book wasn't only denounced by the twitter mob, but also burned publicly, with the actors unbothered by the historical significance of this act.