California is leading a coalition of 20 states in a lawsuit challenging President Donald Trump’s national emergency declaration to fund a wall on the U.S.-Mexico border.

California Gov. Gavin Newsom (D) and Californa Attorney General Xavier Becerra announced a motion for a preliminary injunction on Friday to block the Trump administration from diverting $1.6 billion from the Department of Defense and other earmarked funds to construct a wall at the border.

“The Executive Branch’s power is not unlimited,” Becerra said in a statement, calling Trump’s attempt to fund a wall by declaring a national emergency “unconstitutional.”

Trump declared a national emergency in February after failing to obtain congressional support for a spending bill that would have included $5.7 billion in funding for a border wall. He signed a spending bill that included $1.375 billion for border security but then made the emergency declaration to go around the legislative branch, saying he needed billions more to start work on the barrier.

“California stands united against President Trump’s money-grab to fund his expensive and ineffective wall, which he promised would be paid for by Mexico,” Newsom said in a statement on Friday. “This funding should be spent as it was intended: to support local law enforcement agencies and to fight drug trafficking.”

Newsom and Becerra filed Friday’s motion in the Northern District of California as a follow-up to a February lawsuit challenging Trump’s national emergency declaration. Colorado, Connecticut, Delaware, Hawai’i, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nevada, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Virginia and Wisconsin join California in the lawsuit.

The filing comes a day after House leaders voted to authorize a lawsuit against Trump over his national emergency declaration.

“The President’s sham emergency declaration and unlawful transfers of funds have undermined our democracy, contravening the vote of the bipartisan Congress,” House Speaker Nancy Pelosi (D-Calif.) said in a statement on Thursday.