Mr. Johnson played a video showing animals living in cages and then being electrocuted or having their necks broken. “The evidence of cruelty in the fur industry is overwhelming,” he said.

Local furriers should “diversify” and embrace innovations in the fashion and garment industry that can take the place of fur. “There is no such thing as ‘ethical’ fur, or ‘ecological’ fur, or ‘excellent welfare’ fur,” Mr. Johnson said.

But it was unclear how much support the bill has in the City Council or when Mr. Johnson might seek to bring the measure up for a vote. Mayor Bill de Blasio has said that he supported “the underlying idea” of a ban, but added that he was concerned about the effect on workers in the fur industry.

“I think if something happens here there has to be some sense of how to phase it in, in a way that really does try and protect some jobs,” Mr. de Blasio said in March.

Councilman Chaim Deutsch of Brooklyn said that he opposed the ban for several reasons, including that many Hasidic Jewish men wear hats made of fur, known as shtreimels or spodiks.

“If we ban fur and then you have people that are still out there wearing it, considering the fact that hate crime in New York City is on the rise, people will be targeted on the streets, saying, ‘Why are you wearing this if there’s a fur ban?’” Mr. Deutsch said.

In its current form, the bill includes an exemption for fur items worn as a “matter of religious custom,” but Mr. Deutsch was nonetheless wary.