HBO has come out in defense of its upcoming controversial series Confederate again, arguing it should not be judged before it’s seen, reports The New York Times. HBO announced last month that Game of Thrones show runners David Bennioff and D.B. Weiss will helm the new drama called Confederate. Set in America on the brink of civil war, the series will follow an alternate reality where the Southern states successfully seceded from the Union, and slavery persists.

"We support everybody’s right to express an opinion but the suggestion of irresponsibility on our part is simply undeserved,” the network said in a statement. “We recognize the sensitivity of this project and will treat it with the respect that it deserves.”

HBO is no stranger to controversy, with series like True Blood known for its gory violence and graphic sex scenes. But, it says it “champions intelligent story telling,” which is valid, given its run of critically acclaimed shows like The Sopranos and Veep. Still, Confederate will be a first for HBO tackling the delicate subjects of slavery and race in America.

The announcement of the series has sparked furious debate online, with the hashtag #NoConfederate used on Twitter in a push to ban the series before it starts. Prominent writer Ta-Nehisi Coates, said in a piece in The Atlantic earlier this month that "African Americans do not need science-fiction, or really any fiction, to tell them that that ‘history is still with us.’ It’s right outside our door. It’s in our politics. It’s on our network."

It’s likely that Confederate won’t air at least until 2019, as HBO has said production will not begin until Game of Thrones is wrapped up next year.