The U.S. Supreme Court on Monday is hearing a case that could have major implications for the independence of federal agencies long shielded from the White House.

The case, known as Trump v Slaughter, stems from President Donald Trump's firing in March of Rebecca Kelly Slaughter, alongside another Democratic member of the Federal Trade Commission (FTC).

The court is examining arguments regarding whether Trump had the authority to fire a member of the FTC despite a law that explicitly states that a commissioner can only be removed for 'inefficiency, neglect of duty, or malfeasance in office'.

Ms. Slaughter has previously filed a lawsuit against Trump after she was ousted for being 'inconsistent with [the] Administration's priorities'.

A lower court ruled that Ms. Slaughter's removal from the FTC was illegal, prompting the Trump administration to appeal this ruling to the Supreme Court. A conservative-majority court ordered in September that her firing remain in effect until the case was fully heard.

Trump contends that a president should have complete control over governmental agencies, including those established by Congress to be insulated from presidential involvement.

The FTC, created in 1914 to protect the public from deceptive business practices and unfair competition, operates under laws that allow presidential removals only for valid reasons. Moreover, it mandates that no more than three commissioners belong to the same political party.

Trump appointed Ms. Slaughter in 2018 to fill a Democratic seat on the FTC, and she was subsequently reappointed by President Joe Biden.

Similar removal rules apply to other independent agencies like the National Labor Relations Board.

This legal principle was previously tested in 1935 when President Franklin Roosevelt attempted to dismiss a FTC member; the Supreme Court upheld the independence of specific federal bodies, including the trade commission.

In the landmark ruling known as Humphrey's Executor, the court determined that while the president may sack executive officers without cause, this does not extend to agencies like the FTC, which possess quasi-judicial and quasi-legislative functions.

The Supreme Court is also expected to review a separate case regarding Trump's authority to remove Lisa Cook from the Federal Reserve Board of Governors.