By Madeline Farber

Almost 200 Democratic members of Congress are going to sue President Donald Trump.

On Wednesday, the members agreed to file a lawsuit against Trump, the Washington Post reports. They allege that he has violated constitutional restrictions on taking gifts and benefits from foreign leaders because he still has international business interests.

Sen. Richard Blumenthal (D-Conn.) is the lead senator who filed the complaint in federal district court, according to the Post. Blumenthal said that the lawsuit has 196 congressional plaintiffs, which is more than any other legal action ever taken against a president. Only Democrats have joined the lawsuit as of now, but Republicans are able to join if they wish.

According to a copy of the legal complaint as reviewed by Post, the lawsuit argues that Congress members have special standing because of the Constitution’s “foreign emoluments clause.” The clause says: “[N]o Person holding any Office of Profit or Trust under [the United States], shall, without the Consent of the Congress, accept of any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign State.” The language of the clause, according to the Post, is interpreted as prohibiting the president or any officeholder from accepting a gift, payment or any other benefit from a foreign state without first getting consent from Congress.

Therefore, the lawsuit argues that the president must obtain “the consent of Congress” before accepting any gifts, according to the Post.

The White House was not immediately available for comment when contacted by Fortune.