Legal battle erupts over Trump's massive White House ballroom addition as preservationists challenge the controversial $300 million construction project.

The Trump administration said in a court filing that the White House ballroom construction project must continue for reasons of national security.

The Trump administration said in a court filing Monday that the president’s White House ballroom construction project must continue for unexplained national security reasons and because a preservationists' organization that wants it stopped has no standing to sue. The filing was in response to a lawsuit filed last Friday by the National Trust for Historic Preservation asking a federal judge to halt President Donald Trump's project until it goes through multiple independent reviews and a public comment period and wins approval from Congress. The administration's 36-page filing included a declaration from Matthew C. Quinn, deputy director of the U.S. Secret Service, the agency responsible for the security of the president and other high-ranking officials, that said more work on the site of the former White House East Wing is still needed to meet the agency’s “safety and security requirements.”

The Trump administration says in a court filing that the president’s White House ballroom construction project must continue for unexplained national security reasons.