NEW YORK (AP) — A federal lawsuit seeks to halt the upcoming UFC fight card on the White House South Lawn in a mixed martial arts show timed for President Donald Trump’s 80th birthday and part of the celebration of the nation’s 250th anniversary.

The filing Saturday by the Public Integrity Project on behalf of two Virginia residents contends the Trump administration’s authorization of the June 14 event was unlawful. The lawsuit says such approval violated National Park Service regulations prohibiting sporting events on federal parklands, Congress did not consent to the towering arch overlooking the event space and no environmental review was conducted before the construction.

“This is fundamentally a private, commercial, corrupt use of our most sacred national monuments for private gain,” said Brendan Ballou, a lawyer for the plaintiffs. “And that is what is motivating this lawsuit.”

The White House said in a statement that the legal challenge was “an obstructionist, baseless, and dilatory” attempt to prevent Trump from hosting the fight and that the event was “no different than the various other White House-hosted events on the South Lawn and properly permitted events on the Ellipse and National Mall throughout the year.”

UFC did not immediately respond to a request for comment Sunday.

Crews are erecting an octagon-shaped cage on the South Lawn. Trump has said the finished UFC project will feature “a 5,000-seat arena right outside the front door of the White House.” Additional large screens broadcasting the fights will be set up in a park at the nearby Ellipse, and the UFC has said it plans to issue as many as 85,000 free tickets to accommodate spectators at both locations.

The octagon and surrounding structures are the latest project in the White House building boom Trump is leading.