A federal judge rejected an emergency bid Tuesday by preservationists to halt construction of the White House ballroom, but warned that the Trump administration may eventually have to remove its prep work. 

US District Judge Richard Leon, a George W. Bush appointee, concluded that the preservationists failed to show they faced irreparable harm and stressed that the underground work for the ballroom can’t dictate its eventual shape and size. 

The decision comes a day after the Secret Service warned that halting construction on President Trump’s vaunted White House ballroom could pose “substantial” national security concerns.

Secret Service deputy director Matthew Quinn claimed that the contractor completed most of the “temporary security measures” in the ballroom construction zone, but still has unfinished work.

“Any pause in construction, even temporarily, would leave the contractor’s obligation unfulfilled in this regard and consequently hamper the Secret Service’s ability to meet its statutory obligations and protective mission,” Quinn warned in the Monday filings.

Quinn offered to provide a classified briefing with more specific details about why pausing construction of the White House ballroom could jeopardize national security in the wake of the two assassination attempts on Trump’s life, but refrained from elaborating in the public filing.

The Post reached out to the Secret Service for additional information.

The bleak warning was intended to undercut a lawsuit from the National Trust for Historic Preservation, a congressionally chartered nonprofit tasked with protecting America’s historic buildings.

The National Trust sued the Trump administration last Friday to stop construction of the White House ballroom, arguing that presidents aren’t allowed to unilaterally rip down parts of the executive mansion “without giving the public an opportunity to weigh in.”

In its response to the sprawling lawsuit, the administration revealed that plans for the ritzy ballroom are “not final” and argued that it will have “no significant impact” on the surrounding environment.

Trump’s team also vowed to get input from relevant agencies for the 90,000-square-foot structure, including from the National Capital Planning Commission and the Commission of Fine Arts.

It will seek approval “before above-grade construction occurs,” which is not expected to start until at least April.

Another gripe the National Trust had was a concern that the Trump administration didn’t take necessary environmental concerns into account when it bulldozed the East Wing.

“When the East Wing was demolished, it was over 120 years old, and many buildings of similar age contain environmental hazards—such as, for example, asbestos and lead paint—that must be properly handled,” the lawsuit complained.

“Further, debris from the East Wing has been dumped at a public park, with no apparent plan or regard for its potential hazards.”

The National Trust also underscored that the White House ballroom marks the most significant change to the executive mansion in at least 80 years.

Trump has publicly called for the construction of a White House ballroom for more than a decade and even offered to pay for one during the Obama administration.

The real estate mogul unveiled his ballroom plans in July, with an initial pricetag of $200 million, which has since ballooned to $300 million. The ballroom has been privately funded.

Demolition of the East Wing, historically the domain of the first lady, took place in October.