By Andrea Shalal, Pete Schroeder, Jack Queen and Karen Freifeld

WASHINGTON (Reuters) -President Donald Trump's administration targeted on Tuesday bank regulators, rocket scientists and tax enforcers for dismissal, as a federal judge gave the green light for its unprecedented remaking of the U.S. civil service, at least for now.

With Trump's blessing and praise, tech billionaire Elon Musk's Department of Government Efficiency, or DOGE, has swept through federal agencies slashing thousands of jobs since Trump became president last month and put Musk, his biggest campaign donor, in charge of a drastic overhaul of government.

Trump claimed without evidence on Tuesday the endeavor would save "hundreds of billions of dollars" and heaped praise on Musk as a patriot. Musk's team has said it has saved $55 billion so far, less than 1% of the annual $6.7 trillion federal budget.

The campaign has delighted Republicans for culling a federal workforce they view as bloated, corrupt and insufficiently loyal to Trump, while also taking aim at government agencies that regulate big business and collect taxes.

Democratic critics in turn have raised concerns that Trump is exceeding his constitutional authority and hacking away at popular and critical government programs at the expense of legions of middle-class families.

They complain that Musk has operated as an unchecked freelance operator who has seized access to sensitive government data.

On Tuesday the downsizing extended to NASA, where 1,000 new hires including rocket scientists were expected to be laid off, according to two people familiar with the U.S. space agency's plans. More cuts were deemed possible.

"People are scared and not speaking up to voice dissent or disagreement," said one employee at the 18,000-person agency who spoke on condition of anonymity.

Musk said the complaints were a sign that DOGE was working.

"All we're really try to do here is restore the will of the people through the president and what we're finding is that there's an unelected bureaucracy ... that is implacably opposed to the president and the cabinet," Musk told Fox News in an interview recorded on Friday and aired on Tuesday.

The White House has not said how many people it plans to fire and has given no numbers on the mass layoffs. The information to date has come from employees of federal agencies.

The Office of Personnel Management, which manages the civil service, set a deadline on Tuesday for all government departments to provide a list of probationary employees who have been terminated and those sought to be retained, an OPM spokesperson said.

It remained unclear whether the numbers would be disclosed.

COURT BATTLES

About 20 lawsuits filed in various federal courts challenging Musk's authority have seen mixed results.

In one of the more consequential cases, U.S. District Judge Tanya Chutkan on Tuesday denied a request to place a temporary hold on DOGE. She instead allowed the campaign to continue while underlying litigation plays out.

But Chutkan raised flags about Musk's authority as an independent operator, writing, "Plaintiffs legitimately call into question what appears to be the unchecked authority of an unelected individual and an entity that was not created by Congress and over which it has no oversight."

Congressional Democrats said oversight committee requests for information had gone unanswered, calls to agency officials were not being returned, and details of new policies essential for constituent casework were difficult to come by.

"This is not normal, at all," one Senate committee aide said about the lack of response.

Trump asserted even more executive authority on Tuesday, issuing an order to rein in independent agencies and claiming presidential supervision and control of the entire executive branch except for the Federal Reserve.

The White House identified the Federal Trade Commission (FTC), Federal Communications Commission (FCC) and Securities and Exchange Commission (SEC) as agencies that "have exercised enormous power over the American people without presidential oversight."

The job-cutting continued apace.

Senior officials at the IRS identified at least 7,500 employees for dismissal, according to a person familiar with the matter.

The Federal Deposit Insurance Corporation, which oversees banks, said it had fired an unknown number of new hires, according to an email seen by Reuters.

Layoffs were also expected at the Federal Emergency Management Agency, which handles flood insurance and disaster response, as well as its parent, the Department of Homeland Security, sources said.

Among the workers swept up in the overhaul of dozens of agencies are those reviewing Musk's brain implant company Neuralink.

Musk's role has raised questions about the fate of at least 20 federal investigations and regulatory actions affecting his business empire, Reuters reported last month.

On Tuesday, Trump said he would not let Musk participate in any space-related government decisions.

(Reporting by Nathan Layne, Leah Douglas, Andrea Shalal, Sarah N. Lynch, Joey Roulette, Pete Schroeder, Ted Hesson, Karen Freifeld, Bo Erickson and Jack Queen; Writing by Andy Sullivan and Daniel Trotta; Editing by Leslie Adler and Clarence Fernandez)