Elon Musk has continued his ongoing feud with ex-pal Donald Trump with a new brutal eight-word message shared publically on the social media platform he owns. The world's richest man told his 220.2million followers: "Without me, Trump would have lost the election."

It comes as the pair trade insults publicly about the US's imminent federal funding bill which looks set to increase the nation's borrowing despite pledges made during last year's election campaign. The SpaceX owner spent at least US$288 million to help elect President Trump and other Republican candidates, according to a Washington Post analysis.

However, he appears to have grown disillusioned with White House policies, launching a blistering attack on Trump's signature tax and spending bill.

He has branded it a "disgusting abomination" and called on voters to contact their representatives in Congress to voice their opposition.

"Bankrupting America is not OK!" he wrote on X. "KILL the BILL."

Musk's latest outburst came after Trump said he was "very surprised" and "disappointed" with the criticisms of the Tesla owner.

"Elon and I had a great relationship. I don't know if we will anymore," he told reporters in the White House on Thursday.

Musk headed up the so-called Department of Government Efficiency (DOGE) that sought to slash government spending. Thosudands of federal employees were sacked in the cost-cutting exercise.

Musk announced he was quitting DOGE last week after 129 days on the job, and Trump presented him with a golden key during a congratulatory news conference on May 30.

Speaking to reporters during a news conference with German Chancellor Friedrich Merz on Thursday, Trump said: "We are doing things in that bill that are unbelievable.

"I'm very disappointed because Elon knew the inner workings of this bill better than almost anybody sitting here," he said. "All of a sudden he had a problem. He hasn't said bad about my personally, but I'm sure that will be next."