By Rebecca Davis O'Brien and Sadie Gurman 

Sixteen states on Monday filed a federal lawsuit challenging President Trump's national-emergency declaration to pay for a wall along the U.S.-Mexico border, setting up a showdown with the administration that could go to the Supreme Court and last through the 2020 election.

The complaint, filed in California's Northern District, seeks judicial intervention to stop the order and accuses Mr. Trump of "flagrant disregard for the separation of powers" in a move that allegedly undermined Congress and redirected federal money -- some of which was intended for states -- toward the wall.

"President Trump has veered the country toward a constitutional crisis of his own making," the lawsuit said.

California's Attorney General led the lawsuit and was joined by Colorado, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Michigan, Minnesota, Nevada, New Jersey, New Mexico, New York, Oregon, and Virginia -- all but one of which are led by Democratic governors.

Mr. Trump declared a national emergency Friday, after Congress passed a spending bill without funding for the wall. The move was designed to allow him to access billions of dollars from military-construction projects and other federal sources to build a wall on the border with Mexico. The declaration drew swift condemnation from Democrats and some Republicans in Congress and was widely expected to be challenged in court.

The states seized in part on Mr. Trump's comment Friday that, "I could have done the wall over a longer period of time. I didn't need to do this" as proof that the declaration wasn't an emergency. The lawsuit says "By the President's own admission, an emergency declaration is not necessary," adding that the federal government's data show there "is no national emergency at the southern border that warrants construction of a wall."

The White House didn't immediately comment on the suit.

Write to Rebecca Davis O'Brien at Rebecca.OBrien@wsj.com and Sadie Gurman at sadie.gurman@wsj.com

(END) Dow Jones Newswires

February 18, 2019 20:51 ET (01:51 GMT)