Paramount Skydance chief David Ellison and his tech billionaire dad Larry Ellison have been sued by a Paramount shareholder who alleges they cut an "illegal" deal with President Donald Trump to secure U.S. governmental approval for the takeover of Warner Bros. Discovery.

The lawsuit is a serious threat to Paramount CEO David Ellison's bid to transform his company into a major competitor to Netflix and Disney.

The lawsuit could derail or delay the closing of the deal, which could cost Paramount hundreds of millions of dollars.