HBO came under fire over the weekend after releasing the trailer for Brexit, its upcoming film about the successful Vote Leave campaign that saw the U.K. vote in 2016 to leave the European Union. The Toby Haynes-directed feature, a co-production between BBC Studios, Channel 4 (which will air it in the U.K. on Jan 7) and House Productions and starring a balding Benedict Cumberbatch as Leave campaigner Dominic Cummings, is said by HBO to go “behind the scenes, revealing the personalities, strategies and feuds of the Leave and Remain campaigns.” As shown in the trailer, much of the focus is on these “strategies” and how the Vote Leave campaign spent more than 2.7 million pounds ($3.4 million) on targeting ads at specific groups of people on Facebook, many of whom had never voted before.

But two-and-a-half years on from the referendum — which was won by a narrow 51.9 percent — and the tactics used by Vote Leave are the source of significant controversy in the U.K., where there are ongoing accusations about their legality and there have been calls for a [Robert] Mueller-style investigation into the Leave Campaign. In July, an Electoral Commission probe found that the Leave campaign broke the law by exceeding its 7 million pound ($8.8 million) spending limit by siphoning funds through a separate pro-Brexit group, while the data company it used, Aggregate IQ — a Canadian digital marketing outfit has said was vital to the victory — has linked to Cambridge Analytica. Cummings, meanwhile, has refused to appear before a Parliamentary inquiry into fake news. As such, when the trailer to Brexit (it’s coming out as Brexit: The Uncivil War in the U.K.) dropped, and amid a period of political turmoil as the British government continues to tear itself apart about its European exit deal, not everyone in the U.K. was delighted, particularly with the tagline: “Everyone knows who won. But not everyone knows how.”

Carole Cadwalladr, the award-winning Guardian journalist who broke many of the stories regarding Cambridge Analytica and has been investigating the Vote Leave campaign, was among the most vocal critics, tweeting: “Fuck off @HBO. Imagine if we did this for Trump right now. You are literally interfering in our criminal justice system.”

"Brexit: The Uncivil War is a drama based on extensive and in-depth factual research from a myriad of sources and is an accurate, duly impartial and fair examination of the events of the time and of the people involved," said Channel 4 in a statement. "The biggest political moment of recent British history, Brexit is legitimate territory for a Channel 4 drama to explore and, as our remit calls for, we expect this film to stimulate debate and discussion." The Hollywood Reporter has reached out to HBO for comment. See the trailer above.