Roughly 150 Democratic lawmakers filed a legal brief Thursday in the ongoing White House East Wing litigation, asserting that construction cannot continue until the Trump administration obtains express consent from Congress.

"The President cannot undertake any construction at the White House—much less demolish one of its wings—without clear authorization from Congress, as well as an appropriation of funds to do so," lawyers for the Democrats wrote. 

The coalition of lawmakers is led by Reps. Robert Garcia and Jared Huffman of California, and Rhode Island Sen. Sheldon Whitehouse.

They argue that the president has no right to demolish structures or to build new ones on White House grounds because "[t]he Constitution grants Congress exclusive control over all federal property," and it has yet to approve funding or an authorization for the project.

The administration has contended that a statute permitting the White House to perform routine maintenance and repairs to the executive mansion provides a legal justification for the privately funded $400 million demolition and construction of the East Wing. Congress only appropriated about $2.5 million for such repairs. 

Congress "does not fund largescale construction projects with drop-in-the-bucket funding," the lawmakers wrote in the amicus brief.

The National Trust for Historic Preservation filed a lawsuit against President Trump late last year. In March, a federal judge ruled that construction could not proceed until Congress green-lit the project. A panel of appellate judges has temporarily allowed construction to continue and will hear arguments next week. 

Todd Blanche, the acting attorney general, has argued in recent filings that reconstruction of the East Wing — which includes a ballroom, kitchen space and secure facilities — is a matter of national security. He has claimed the shootings at the White House Correspondents' Dinner and near the Eisenhower Executive Office Building last Saturday make completion of the project all the more urgent. 

Senate Republicans briefly contemplated a measure that would have provided a billion dollars to bolster ballroom security, but that provision has since been dropped from a larger GOP bill. 

"President Trump is building a billion-dollar ballroom. Everyone should be disgusted by his illegal and unconstitutional vanity project. We are fighting this in court," said Garcia, the top Democrat on the House Oversight Committee.

Two other interested parties filed amici briefs in the ballroom case this week. 

On Wednesday, Citizens for Responsibility and Ethics in Washington and the Campaign Legal Center, two nonprofits focused on government ethics, wrote that accepting ballroom donations from companies and individuals with business before the government presents a conflict of interest. 

Congress should appropriate money for the ballroom, the ethics groups asserted. "This is a check against both Executive extravagance and the risk of corrupting influence."

A consortium of architects and preservationists filed a separate brief, also taking a stand against the administration, arguing, "The president has no inherent authority to direct destruction of historic federal property within a national park and then use private funds to satisfy his personal quest to build a massive, discordant, above-ground ballroom."