Oscar-winning actress Jennifer Hudson has come under attack from a South African actors’ union after the American star was cast as the ex-con former wife of the country’s former president, Nelson Mandela, in a new biopic.

The former American Idol-turned-Dreamgirl is set to portray Winnie Mandela in South African filmmaker Darrell J. Roodt’s new project Winnie, about the famous politician’s longtime wife. However, Jennifer’s gig has caused uproar among the members of the Creative Workers Union of South Africa, who insist a local South African star should have been cast as the title character in a movie so important to the country’s history.

The Union’s secretary general, Oupa Lebogo, is even threatening to boycott the feature if J-Hud remains in the lead role.

“This decision must be reversed, it must be stopped now. If the matter doesn’t come up for a discussion, we will push for a moratorium to be placed on the film,” Lebogo says.