Elon Musk warned that he would boost primary challenges against Republican lawmakers who vote for President Trump's so-called "big, beautiful bill."

The neuroscientist, whose company was partly bankrolled by Musk, gave Trump a shocking heads-up of what the president can expect from the tech mogul in the future.

(Reuters) -Billionaire Elon Musk reiterated his criticism of U.S. President Donald Trump's spending legislation on Monday, arguing that it underscores the need for a new political party. The Tesla chief slammed the "insane spending" of the bill,

U.S. Senate Republicans on Monday evening were still trying to pass President Donald Trump's sweeping tax-cut and spending bill, despite divisions within the party about its expected $3.3 trillion hit to the nation's debt pile.

The US Senate has begun a marathon vote on a sprawling budget that is critical to President Donald Trump's agenda, but the spending plan is hanging in the balance after weeks of fraught negotiations.