A federal judge late Thursday temporarily blocked construction of President Trump's triumphal arch hours after the National Capital Planning Commission voted 8-4 to approve it.

U.S. District Judge Tanya Chutkan issued a temporary restraining order barring "construction-related activity" for 14 days while the lawsuits against the project proceed, CBS News reported. She wrote that the plaintiffs are "likely to succeed" in showing the government did not follow required legal processes, and pointed to "tangible economic harms" from traffic problems to support standing for Virginia and the District of Columbia.

The challengers are the attorneys general of Virginia and D.C., who argued the project would cause irreparable harm, and a group of Vietnam War veterans that includes Michael Lemmon and Shaun Byrnes. Their core argument is that the arch needs approval from Congress, which they say it lacks.

The White House has not backed down. "We are confident we will be fully vindicated as this litigation proceeds," spokesman Davis Ingle said.

The arch is planned for Memorial Circle, across the Potomac from the Lincoln Memorial and next to Arlington National Cemetery. It would stand 166 feet tall, 250 feet with the three gilded figures on top, and include an observation deck. The administration expects between 2,000 and 22,400 visitors a day and about three years of construction.

Who pays for it, and how much it will cost, is still unclear. It is also unclear how soon work could begin if the order lapses.

Chutkan had already signaled she might act. In September she ordered the administration to give 48 hours' notice before any activity at the site, and earlier this week she set multiple notification deadlines, including a requirement to be told within an hour of any decision by the planning commission.