(The Hill) — Sen. Bernie Sanders (I-Vt.) on Wednesday said some of the bold steps that billionaire tech entrepreneur Elon Musk has taken to tackle waste in the federal government are “illegal.”

“Nothing wrong with looking for waste in the kinds of bureaucracy that exist. I think we can do a whole lot to get rid of the waste, the fraud, the excessive bureaucracy that exists in government especially, by the way, in the Defense Department,” Sanders told CNN’s Anderson Cooper on “AC360” Wednesday.

“What is wrong right now is one simple reality: What Musk is doing is illegal and unconstitutional,” Sanders added.

Musk’s team at the Department of Government Efficiency (DOGE) has instituted sweeping changes to the executive branch in the first weeks of President Donald Trump’s administration, prompting questions among critics about the legal basis for some of his moves.

The billionaire moved to lock federal workers out of the U.S. Agency for International Development (USAID), which Congress funds annually through appropriations bills for the State Department and foreign operations. He gained access to the Treasury Department’s federal payment system, and, under Musk’s influence, many federal workers have been offered buyouts.

“You cannot go into an agency like USAID and essentially fire everybody and get rid of that agency,” Sanders said. “That’s an agency that was created by Congress.”

“They want to get rid of USAID? Fine. Come to the Congress. Make your case,” he continued. “You can’t do it unilaterally.”

Sanders, in the interview, also said he thinks the U.S. government has become an oligarchy. He criticized Musk for spending more than $200 million to boost Trump’s campaign in the 2024 election cycle and noted that, already, Musk’s net worth has increased by more than $150 million since Trump was sworn in.

“You tell me whether or not we are living in an oligarchy,” Sanders said. “And I think the function of government under Trump, under Elon Musk, will not be to serve ordinary people, but to make the very richest people in this country even richer.”