A federal appeals court ordered Friday that the construction of the proposed White House ballroom must get congressional approval to proceed, dealing President Donald Trump another setback in his ambitious project for the executive mansion.The U.S. Court of Appeals for the D.C. Circuit ruled 2-1 that construction must stop on the extensive renovation of the East Wing, which includes a new ballroom, because Congress has control over how the White House may be changed, not the executive branch, despite it being the executive mansion. The two judges sided with the National Trust for Historic Preservation, a preservationist group, which sued the Trump administration late last year when construction on the ballroom began.“The Constitution assigns Congress—not the Executive—the responsibility to decide whether proposed changes to the physical design of the White House may proceed, even where those changes are said to serve security interests,” the ruling said. “The Defendants have not shown that Congress delegated that authority to either the President or the National Park Service. Whether or not a massive ballroom should be constructed is for Congress to decide and is not a matter for Executive self-help.”