The GAO found that the administration broke the Impoundment Control Act — a 1974 law that provides a mechanism for the executive branch to request that Congress reconsider a funding decision that’s been signed into law.

“This bombshell legal opinion from the independent Government Accountability Office demonstrates, without a doubt, that the Trump administration illegally withheld security assistance from Ukraine” said Sen. Chris Van Hollen (D-Md.), who requested GAO write the report in December.

The GAO report was widely expected to stay away from the specific House impeachment charges. House lawmakers impeached Trump on two counts, abuse of power and obstruction of Congress. Lawmakers alleged that the president abused the power of his office in withholding the money as leverage to pressure Zelensky into publicly announcing investigations that would undermine a political rival, and then obstructed the investigation into those actions.