UFC’s Freedom 250 event on the South Lawn of the White House is less than a week away, but a newly filed federal lawsuit seeks to halt the mixed-martial arts competition.

The Public Integrity Project, a Washington, D.C.-based organization seeking to combat political and corporate corruption, filed suit in the U.S. District Court for the District of Columbia, alleging that the event violated strict National Park Service regulations, failed to secure Congressional approval, and did not involve a required environmental review.

Among the core issues is the construction of a 600-ton, claw-shaped structure that hangs over the UFC octagon on the South Lawn and dwarfs the adjacent White House, and the separate staging of a pre-fight press conference at the Lincoln Memorial.

The suit seeks a declaration that the UFC event is unlawful, and an emergency restraining order that would bring an immediate end to the use of the South Lawn and Lincoln Memorial for these functions. UFC Freedom 250, headlined by a light heavyweight unification fight between Ilia Topuria and Justin Gaethje, is set for Sunday night.

“The issue isn’t strictly about having UFC, or any sporting event, on these grounds. It’s about the corruption around it,” Brendan Ballou, Public Integrity Project CEO, tells Front Office Sports. “This is about having a for-profit enterprise on these grounds, with VIP packages for more than $1 million, sponsored in part by a cryptocurrency exchange, run on a subscription-based streaming service, and by a company [UFC parent TKO Group Holdings] that the president has personally invested in. There was a legal, non-corrupt way to do this.”