Layoffs have begun at the Department of Health and Human Services, including at the Food and Drug Administration and the Centers for Disease Control and Prevention.

A union that represents 150,000 U.S. government employees filed a lawsuit on Monday seeking to block President Donald Trump from stripping hundreds of thousands of federal workers of the ability to collectively bargain with government agencies through their unions.

The National Treasury Employees union filed suit against the Trump administration in federal court in Washington, D.C., on Monday, over the White House order eliminating collective bargaining rights for two-thirds of the federal workforce.

A major restructuring at US Health and Human Services Department is set to cut up to 10,000 jobs, targeting positions deemed redundant or in high-cost regions. The overhaul follows Trump's executive order removing collective bargaining rights from unions and aims to create efficiency.

The cuts are part of a plan by President Donald Trump and billionaire ally Elon Musk to shrink staffing levels in federal agencies.