The first lawsuits challenging the legality of President Donald Trump s national emergency declaration began rolling in on Friday, and lawmakers say more are likely to follow.

Citizens for Responsibility and Ethics in Washington came out the gate first with a lawsuit alleging that the Department of Justice failed to provide documents concerning the presidents legal authority to invoke emergency powers over a border wall.

Americans deserve to know the true basis for President Trumps unprecedented decision to enact emergency powers to pay for a border wall, CREW Executive Director Noah Bookbinder said in a statement. Were suing because the government has so far failed to produce the requested documents or provide an explanation for their delay.

The announcement came the same day Trump confirmed he will use the declaration to divert about $3.6 billion the Defense Department had allocated for construction projects and $2.5 billion earmarked for counterdrug activities in order to fund his long-promised wall on the U.S.-Mexico border a project Congress refused to fully fund in the spending bill it passed Thursday.

The American Civil Liberties Union announced Friday that it will file a lawsuit early next week arguing that Trump cannot legally use the emergency declaration to evade those funding limits imposed by Congress.

The Constitution assigns Congress the power of the purse, and no prior president has ever tried to use emergency powers to fund a chosen project particularly a permanent, large-scale domestic project such as this against congressional will, Dror Ladin, staff attorney with the ACLUs National Security Project, said in a statement. This is obviously improper.

Other lawsuits are likely to follow. In a press conference on Friday, California Gov. Gavin Newsom (D) and Attorney General Xavier Becerra said they are planning to sue after reviewing the declaration.

Donald Trump , well see you in court, the governor said.

Becerra said they are working closely with several other states that feel the same way, hinting at a multistate legal effort.

Democrats in Congress have also signaled theyre ready to go to court. Soon after Trumps announcement Friday, House Speaker Nancy Pelosi (D-Calif.) and Senate Minority Leader Chuck Schumer (D-N.Y.) issued a joint statement , saying, Congress will defend our constitutional authorities in the Congress, in the Courts, and in the public, using every remedy available.

Plenty of past presidents have declared national emergencies something Trump has cited to normalize his plans but its unprecedented for a president to declare one as a means of bypassing Congress to pay for a project lawmakers wont endorse.