Elle Fanning has been cast as a transgender teenage boy in a new film.

The 16-year-old actress – sister to Dakota Fanning – has been cast alongside Susan Sarandon and Naomi Watts in indie drama Three Generations, which will follow Fanning’s character Ray as he transitions to male.

Watts will play Ray’s mother Maggie, who is struggling to cope with the transition, while Sarandon will in turn play Maggie’s mother – who is in a lesbian relationship.

The film has attracted criticism from some transgender rights advocates for casting a cisgender (non-trans) actress in the role, instead of hiring a trans actor to play the part.

Oscar-winning Dallas Buyers Club received similar criticism when Jared Leto was cast as a transgender woman, as did Amazon’s drama Transparent for casting Jeffrey Tambor.

Jill Solloway, the creator of Transparent, has committed to hiring a transgender writer for the show’s second season, conceding: “No matter what we did, we were always going to be otherising Maura in some way.

“And in the same way where I wouldn’t want a man to say, ‘I can have a writers room full of men and we can write women just fine’ – I can’t say that I can create a show about a trans woman and not have a trans woman writing for me.

“It’s absolutely necessary, and it’s gonna change the show.”

Filming is set to begin on Three Generations this month in New York, and it is tipped for a 2015 release.