A pre-emptive petition calling for studio Disney to avoid “whitewashing” the role of Mulan in its upcoming live-action remake of the 1998 animated tale has gathered more than 20,000 signatures.

Campaigners are calling for the title role, based on the Chinese fable of female soldier Fa Mulan who dressed as a man in order to take up arms against Genghis Khan, to be played by an actor of Asian extraction. In Disney’s earlier take on the story, Mulan was voiced by Macau-born American actor Ming-Na Wen, who currently appears in the Marvel superhero TV show Agents of S.H.I.E.L.D.



“Whitewashing, the practice of casting white Caucasian actors and actresses in roles originally meant to be characters of colour, is all too common in Hollywood,” reads the petition. “The Last Airbender, Pan, the upcoming Ghost in the Shell adaptation, and many, many others have demonstrated this problem. Disney just announced it will develop a live-action Mulan film. Take a stand against whitewashing in our media. Sign this petition to tell Disney that we demand to see them cast an Asian Mulan!”



A similar petition against Scarlett Johansson’s casting in the upcoming Hollywood remake of classic anime Ghost in the Shell garnered 44,000 signatures earlier this year. Petition organiser Julie Rodriguez cited a 2013 survey that suggested Asian characters make up only 4.4% of speaking roles in top-grossing Hollywood films.



The Mulan petition, posted by Natalie Molnar, argues that whitewashing implies that people of colour “cannot be heroes” and “perpetuates a standard of beauty and goodness wherein whites are considered the ideal and norm”. The practice also damages the confidence of young filmgoers of ethnic minority origin, it argues, and limits opportunities for nonwhite actors.



Hollywood’s history of casting white actors in east Asian roles runs all the way back to 1956 epic The Conqueror, in which John Wayne starred as a suspiciously midwestern-accented Genghis Khan, and 1961’s Breakfast at Tiffany’s, which featured bucktoothed Mickey Rooney as the offensive “Japanese” IY Yunioshi. Last year veteran British director Ridley Scott’s biblical epic Exodus: Gods and Kings was criticised for casting famous white actors Christian Bale and Joel Edgerton as figures who lived in the Middle East and north Africa.



Disney’s new take on Mulan will be based on a script by Elizabeth Martin and Lauren Hynek, according to reports last month.