A U.S. judge has temporarily halted President Donald Trump's White House ballroom construction project, ruling that proper procedures were not followed before the project began.


The decision comes after the White House was sued by the National Trust for Historic Preservation.


I have concluded that the National Trust is likely to succeed on the merits because no statute comes close to giving the President the authority he claims to have, said Judge Richard Leon.


Trump criticized the ruling on his social media platform, saying the project is going well, and will be the finest Building of its kind anywhere in the World.


The Trump administration previously said its plan was more economical than renovating the East Wing and noted that many presidents made changes to the White House.


Leon’s ruling, published on Tuesday, continued: The President of the United States is the steward of the White House for future generations of First Families. He is not, however, the owner!


(U)nless and until Congress blesses this project through statutory authorization, construction has to stop! added the judge, who was appointed by President George W. Bush.


The 35-page ruling uses a large number of exclamation points, arguing that Congress must give approval in order for the project to resume.


The order takes effect in 14 days, allowing a possible appeal.


In the lawsuit, the preservation group argued that the White House broke the law by beginning construction without filing plans with the National Capital Planning Commission, not seeking an environmental assessment, and declining to seek authorization from Congress.


It also alleged Trump was violating the U.S. Constitution, which reserves to Congress the right to dispose of and make all rules regarding property belonging to the United States.


In his conclusion, Leon wrote that with White House approval from Congress, the American people will benefit from the branches of Government exercising their constitutionally prescribed roles.


Not a bad outcome, that!


The East Wing, constructed in 1902, was demolished in October to make way for Trump's multi-million dollar ballroom.


Since then, the proposed blueprint has expanded from a ballroom with a capacity of 500 people to a space that can fit 1,350 guests.


The White House says the project is expected to cost $400 million and is being funded entirely by private donors.


Reacting to the judge's decision, Trump wrote on his Truth Social account: The National Trust for Historic Preservation sues me for a Ballroom that is under budget, ahead of schedule, being built at no cost to the Taxpayer, and will be the finest Building of its kind anywhere in the World.