A federal US judge issued a preliminary injunction on Tuesday blocking further construction of the White House ballroom. Judge Richard Leon ruled that proper procedures were not followed before the project began, after the White House was sued by The National Trust for Historic Preservation.

The ruling stated: "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. 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 authorisation, construction has to stop!" It takes effect in 14 days, in which time an appeal can be made.

It also did not seek an environmental assessment of the project and or authorisation from Congress, the group said.

They alleged Donald Trump violated the US Constitution, "which reserves to Congress the right to dispose of and make all rules regarding property belonging to the United States".

The blueprints for the ballroom, which Mr Trump says is being paid for by private donors, have since expanded from 500-capaicty venue to 1,350.