The Supreme Court on Tuesday cleared the way for President Donald Trump’s plans to downsize the federal workforce despite warnings that critical government services will be lost and hundreds of thousands of federal employees will be out of their jobs.

The justices overrode lower court orders that temporarily froze the cuts, which have been led by the Department of Government Efficiency.

The court said in an unsigned order that no specific cuts were in front of the justices, only an executive order issued by Trump and an administration directive for agencies to undertake job reductions.

Justice Ketanji Brown Jackson was the only dissenting vote, accusing her colleagues of a “demonstrated enthusiasm for greenlighting this President’s legally dubious actions in an emergency posture.”

Jackson warned of enormous real-world consequences. “This executive action promises mass employee terminations, widespread cancellation of federal programs and services, and the dismantling of much of the Federal Government as Congress has created it,” she wrote.

The high court action continued a remarkable winning streak for Trump, who the justices have allowed to move forward with significant parts of his plan to remake the federal government. The Supreme Court’s intervention so far has been on the frequent emergency appeals the Justice Department has filed objecting to lower-court rulings as improperly intruding on presidential authority.

The Republican president has repeatedly said voters gave him a mandate for the work, and he tapped billionaire ally Elon Musk to lead the charge through DOGE. Musk recently left his role.

“Today’s U.S. Supreme Court ruling is another definitive victory for the President and his administration. It clearly rebukes the continued assaults on the President’s constitutionally authorized executive powers by leftist judges who are trying to prevent the President from achieving government efficiency across the federal government,” White House spokesperson Harrison Fields said in a statement.

Tens of thousands of federal workers have been fired, have left their jobs via deferred resignation programs or have been placed on leave. There is no official figure for the job cuts, but at least 75,000 federal employees took deferred resignation and thousands of probationary workers have already been let go.

In May, U.S. District Judge Susan Illston found that Trump’s administration needs congressional approval to make sizable reductions to the federal workforce. By a 2-1 vote, a panel of the U.S. 9th Circuit Court of Appeals refused to block Illston’s order, finding that the downsizing could have broader effects, including on the nation’s food-safety system and health care for veterans.

Illston directed numerous federal agencies to halt acting on the president’s workforce executive order signed in February and a subsequent memo issued by DOGE and the Office of Personnel Management. Illston was nominated by former Democratic President Bill Clinton.

The labor unions and nonprofit groups that sued over the downsizing offered the justices several examples of what would happen if it were allowed to take effect, including cuts of 40% to 50% at several agencies. Baltimore, Chicago and San Francisco were among cities that also sued.

“Today’s decision has dealt a serious blow to our democracy and puts services that the American people rely on in grave jeopardy. This decision does not change the simple and clear fact that reorganizing government functions and laying off federal workers en masse haphazardly without any congressional approval is not allowed by our Constitution,” the parties that sued said in a joint statement.

Among the agencies affected by the order are the departments of Agriculture, Energy, Labor, the Interior, State, the Treasury and Veterans Affairs. It also applies to the National Science Foundation, Small Business Association, Social Security Administration and Environmental Protection Agency.