The Vote Audrey clip features actress Zoe Kazan going on the campaign trail wearing pieces from Rachel Antonoff's new range for retailer H&M's sister brand & Other Stories.
Antonoff tells Style.com, "The story for the film was all Lena. She came up with the idea, and we all loved it immediately...
"I feel films are such a good way to bring people into the world we see the clothes living in. It’s really the one opportunity to present the big picture."
Sharing news of the fashion venture on Twitter.com, Dunham writes, "It is pure & utter joy to collaborate with @rachelantonoff & @zoeinthecities".
Dunham previously used her filmmaking talents to advertise the designer's self-titled label in 2013.
The actress has been dating fun. star Jack Antonoff since 2012.