The leaders of the Senate Judiciary Committee sent a rare bipartisan letter to President Trump demanding an explanation for his firing of 17 inspectors general (IG) in one night.

The rebuke said Trump violated the law by failing to give Congress 30 days’ notice and a rationale for the removal for each of the watchdogs at the 18 agencies where they provided oversight.

“Congress was not provided the legally required 30-day notice and case-specific reasons for removal, as required by law. Accordingly, we request that you provide that information immediately,” Sens. Chuck Grassley (R-Iowa) and Dick Durbin (D-Ill.) wrote in the joint letter.

“While IGs aren’t immune from committing acts requiring their removal, and they can be removed by the president, the law must be followed. The communication to Congress must contain more than just broad and vague statements, rather it must include sufficient facts and details to assure Congress and the public that the termination is due to real concerns about the Inspector General’s ability to carry out their mission.”

Trump late Friday fired the group, removing some of his own prior appointees. The ousted watchdogs came from the Defense Department, State Department, Energy Department, Department of Housing and Urban Development and Department of Veterans Affairs, among others.

The move has sparked alarm among those who say it will undoubtedly impact independent oversight.

Speaking to reporters shortly before the letter was released, White House press secretary Karoline Leavitt defended Trump’s firing of the inspectors general.

“He is the executive of the executive branch, and therefore he has the power to fire anyone within the executive branch that he wishes to,” she said.