Tech billionaire Elon Musk has launched an extraordinary attack on Donald Trump's sprawling tax cuts legislation, set to add $US3 trillion ($4.64 trillion) to the nation's debt, calling it a "disgusting abomination".
Just days after leaving his role as advisor to the US president, the Tesla entrepreneur and Republican donor called the mammoth policy package "outrageous".
The legislation would see the US administration extend tax relief through budget cuts which are projected to strip healthcare from millions of low-income Americans who rely on Medicaid.
The legislation, which Mr Trump is calling his "big, beautiful bill", passed the House of Representatives earlier this week and is likely to be the subject of fierce debate in the Senate.
Now, Mr Musk, who until recently held a cost-cutting role in the Trump administration, has intervened to place on record his opposition.
Posting on X, he said he "just can't stand it anymore", adding: "This massive, outrageous, pork-filled Congressional spending bill is a disgusting abomination.
"Shame on those who voted for it: you know you did wrong. You know it."
When White House press secretary Karoline Leavitt was asked how angry she thought Mr Trump would be about Mr Musk's tweet, she said it wouldn't change the president's stance on the bill.
"Look, the president already knows where Elon Musk stood on this bill. It doesn't change the president's opinion. This is one big, beautiful bill and he's sticking to it," she said at a press conference.
The White House said the legislation will spur robust economic growth to neutralise its potential to blow up America's already burgeoning debt pile, which has ballooned to $US36.9 trillion.
But several independent analyses have found that — even taking growth into account — it will add between $US2.5 trillion and $US3.1 trillion to deficits over the next decade.
The nonpartisan Congressional Budget Office, meanwhile, found that the combined effects of tax cuts and cost savings would result in a significant transfer of wealth from the poorest 10 per cent to the richest 10 per cent.
Republicans muscled the measure through the House by a single vote on May 22, a combination of bargaining with vote holdouts on policies and deploying Mr Trump himself to twist arms.
House Speaker Mike Johnson is now pleading with the Senate not to alter the bill too much, as any tweaks will need to go back to the lower chamber.
ABC/wires
