Plaintiffs in a lawsuit trying to stop the Trump administration from building a triumphal arch along the Potomac River are asking a federal judge to halt all construction plans, one day after the National Park Service signaled it would begin work November 5. GARY FIELDS WASHINGTON — Plaintiffs in a lawsuit trying to stop the Trump administration from building a triumphal arch along the Potomac River asked a federal judge on Thursday to halt all construction plans, one day after the National Park Service signaled it would begin work Nov. 5. The plaintiffs — three veterans and a retired architectural historian — asked U.S. District Judge Tanya Chutkan to prohibit the administration and the National Park Service “from taking any steps to construct, or to direct or facilitate construction of, any structure in Memorial Circle, absent congressional authorization, during the pendency of this litigation.”The NPS and the executive office of the president filed a notice Wednesday in the lawsuit saying they planned to possibly begin construction as early as Nov. 5, pending the approval of the construction by the National Capital Planning Commission. The commission is scheduled to meet that day to consider final approval of the site and building plans.

The government’s notice said construction could begin once that approval was finished, the Interior Department issued a final decision authorizing construction and the proper notification was published. “NPS may publish such notice as early as November 5, 2026, and construction could commence as early as November 5, 2026,” the notice said.

The plaintiffs’ filing Thursday said notification “makes clear that the defendants have no intention of awaiting this court’s decision on the cross-motions for summary judgment and have every intention of imminently beginning construction of the arch on Memorial Circle.”Though the arch has received early approval from the U.S. Commission of Fine Arts, whose members were all tapped by President Donald Trump, the plaintiffs sued in federal court in Washington, D.C., saying the project needs to be approved by Congress.

The Public Citizen Litigation Group, which is one of the legal groups representing the plaintiffs, cited several projects being pursued by the administration that had moved forward with work despite pending lawsuits. Chutkan ordered the two sides to meet and file a briefing schedule by noon Friday.

The arch is one of several projects around Washington that President Donald Trump has undertaken as he remakes the city, from renovating one of its storied public golf courses to threatening to demolish the John F. Kennedy Center for the Performing Arts. Just this week, plaintiffs in the East Potomac Park golf course case argued in a five-hour hearing that the Trump had made clear that construction plans were forthcoming, despite the pending litigation.

The lawsuit in federal court in Washington is one of two challenging construction of the arch. The Arlington County Board in Virginia filed a lawsuit earlier this month opposing the construction of the Triumphal Arch, becoming the first governmental body to take legal action against the planned monument.

That lawsuit, filed in the Eastern District of Virginia, criticized the speed at which the project slated for Memorial Circle has moved without going through the full review process. The administration disputed that claim.