U.S. Senate Republicans were struggling to pass President Donald Trump's sweeping tax-cut and spending bill early on Tuesday, amid deep divisions within the party about its expected $3.3 trillion hit to the nation's debt pile.

Senate Republicans can afford to lose no more than three of their own votes on the bill, but two already are opposed and others remained undecided.

Musk threatened to launch a new political party and launch primary fights against Republican candidates if the bill passes.