Washington, Jun 4 (AP) Elon Musk blasted President Donald Trump's "big, beautiful bill" of tax breaks and spending cuts as a "disgusting abomination" on Tuesday, testing the limits of his political influence as he targeted the centerpiece of Republicans' legislative agenda.

The broadside, which Musk issued on his social media platform X, came just days after the president gave him a celebratory Oval Office farewell that marked the end of his work for the administration, where he spearheaded the Department of Government Efficiency.

"I'm sorry, but I just can't stand it anymore," Musk posted on X. "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." The legislation, which has passed the House and is currently under debate in the Senate, would curtail subsidies that benefit Tesla, Musk's electric automaker.

The tech billionaire followed his criticism with a threat aimed at Republicans.

"In November next year, we fire all politicians who betrayed the American people," he wrote in another X post.

It's a sharp shift for Musk, the world's richest person, who spent at least $250 million supporting Trump's campaign last year. He previously pledged to help defeat Republican lawmakers deemed insufficiently loyal to Trump, but now he's suggesting voting them out if they advance the president's legislative priority.

However, it's unclear how Musk will follow through on his criticism. He recently said he would spend "a lot less" on political campaigns, though he left the door open to political involvement "if I see a reason." The tech titan's missives could cause headaches for Republicans on Capitol Hill, who face conflicting demands from Trump and their party's wealthiest benefactor.

Alex Conant, a Republican strategist, said "it's not helpful" to have Musk criticising the legislation, but he doesn't expect lawmakers to side with Musk over Trump.

"Senate Republicans are not going to let the tax cuts expire," Conant said. "It just makes leadership's job that much harder to wrangle the holdouts." Trump can change the outcome in Republican primaries with his endorsements, but Musk doesn't wield that level of influence, Conant said.

"No matter what Elon Musk or anybody else says — and I don't want to diminish him because I don't think that's fair — it's still going to be second fiddle to President Trump," said Republican West Virginia Sen. Shelley Moore Capito.

Musk's business interests stand to take a hit if lawmakers approve Trump's bill, which would slash funding for electric vehicles and related technologies. Musk is the chief executive of Tesla, the nation's largest electric vehicle manufacturer, and SpaceX, which has massive defence contracts.

Last month, Musk said he was "disappointed" by the spending bill, a much milder criticism than the broadside he levelled Tuesday.

The budget package seeks to extend tax cuts approved in 2017, during Trump's first term at the White House, and add new ones he campaigned on. It also includes a massive buildup of $350 billion for border security, deportations and national security.

To defray some of the lost tax revenue to the government and limit piling onto the nation's $36 trillion debt load, Republicans want to reduce federal spending by imposing work requirements for some Americans who rely on government safety net services.

Musk's post threw another hurdle in front of Senate Majority Leader John Thune's already complex task to pass a bill in time for Trump to achieve his goal of signing it by July 4. The South Dakota Republican has few votes to spare in the GOP's slim 53-seat majority.

Two of the Senate's most fiscally hawkish Republicans quickly backed Musk.

"We can and must do better," Kentucky Sen. Rand Paul wrote on X. Utah Sen. Mike Lee said "federal spending has become excessive," adding that it causes inflation and "weaponises government." Still, Trump enjoys fierce loyalty among the GOP base, and in the end, his opinion may be the only one that matters.

White House press secretary Karoline Leavitt played down Musk's criticism.

"The president already knows where Elon Musk stood on this bill," Leavitt said, and Musk's post "doesn't change the president's opinion." The tension in the GOP delighted Democrats, who found themselves in the unlikely position of siding with Musk. Democrats are waging an all-out political assault on GOP proposals to cut Medicaid, food stamps and green energy investments to help pay for more than $4.5 trillion in tax cuts — with many lawmakers being hammered at boisterous town halls back home.

"We're in complete agreement," House Minority Leader Hakeem Jeffries said of Musk. The New York Democratic lawmaker stood alongside a poster-sized printout of Musk's post during a Capitol news conference.

The last time Musk weighed in significantly on legislation, the scenario was far different. His power was ascendant after the election, with Trump joining him for a rocket test in Texas and appointing him to spearhead DOGE.

During the transition period, Musk started whipping up opposition to legislation that would prevent a government shutdown, posting about it repeatedly on X. Trump soon weighed in, encouraging Republicans to back out of a bipartisan deal. Lawmakers eventually patched together a new agreement. (AP) AMJ AMJ