BERLIN — A simmering linguistic controversy has flared up in Germany, with a group of more than 70 influential figures publishing an appeal against the use of gender-neutral terms.

The group issued the letter on Wednesday. On an accompanying petition, they said they were responding in part to a recent decision by the city of Hanover to officially adopt language practices including the so-called gender star — an asterisk that invites readers to choose between gendered spellings.

“The so-called gender-neutral language is first based on a general error; second, produces a wealth of ridiculous linguistic structures; and third, cannot be sustained consistently,” the signatories, who include writers, lawyers, journalists, teachers, linguists and a former head of Germany’s domestic intelligence agency, assert.

“This whole contortion of the language leads to something that is illegible — and hard to understand,” said Oliver Baer, the managing director of Verein Deutsche Sprache, an organization that describes itself as dedicated to promoting the use of German, claims about 34,000 members and helped to write and distribute the letter.