Dec. 17 (Reuters) - President Donald Trump may pursue construction of a massive White House ballroom on the site of the demolished East Wing for now, a federal judge ruled on Wednesday, rejecting an emergency bid by preservationists who call it an abuse of power.

U.S. District Judge Richard Leon denied the National Trust’s bid for a temporary restraining order, saying it failed to show “irreparable harm” at this stage in its lawsuit, but said the government must be prepared to undo any below-ground construction that dictates a specific design.

Since his January return to office, the Republican president has installed gold decorations throughout the Oval Office and paved over the lawn of the Rose Garden to create a patio resembling the setting at his Mar-a-Lago estate in Florida.

The White House and preservation group did not immediately respond to requests for comment.

The 90,000-square-foot (8,360 square-meter) ballroom Trump envisions would dwarf those renovations. In comments at a Hanukkah reception at the White House on Dec. 16, he said his ballroom would cost $400 million, up from an earlier $300 million estimate.