Elon Musk announces he is forming the “America Party”, as his feud with US President Donald Trump deteriorates further.

The announcement comes after Mr Trump signed his self-styled “big, beautiful” tax-cut and spending bill into law on Friday.

Mr Musk has previously said he would start spending money to unseat members of congress who supported the bill.

The tattered relationship between Donald Trump and his main campaign financier Elon Musk has taken another fractious turn, with the space and automotive billionaire announcing the formation of a new political party.

A day after asking his followers on his X platform whether a new party should be created, the space and automotive billionaire announced the move on Saturday.

“Today, the America Party is formed to give you back your freedom,” he posted.

“By a factor of 2 to 1, you want a new political party and you shall have it!”

The announcement from Mr Musk, Mr Trump’s main campaign financier, comes after the president signed his self-styled “big, beautiful” tax cut and spending bill into law on Friday.

Mr Musk had fiercely opposed the bill, saying it would bankrupt America.

Mr Musk, who became the world’s richest man thanks to his Tesla car company and his SpaceX satellite firm, spent hundreds of millions on Mr Trump’s election and led the Department of Government Efficiency, aimed at slashing government spending, from the start of the president’s second term.

The two have since fallen out spectacularly over disagreements about the bill.

The billionaire said previously that he would start a new political party and spend money to unseat members of Congress who supported the bill.

This week, Mr Trump threatened to cut off the billions of dollars in subsidies that Mr Musk’s companies received from the federal government.

Republicans have expressed concern that Mr Musk’s on-again, off-again feud with Mr Trump could hurt their chances to protect their majority in the 2026 midterm congressional elections.

Asked on X what was the one thing that made him go from loving Mr Trump to attacking him, Mr Musk said: “Increasing the deficit from an already insane $2T under Biden to $2.5T. This will bankrupt the country.”

He referenced the growth of Greece from subjugation to pre-eminence in the ancient world in another post.

“The way we’re going to crack the uni party system is by using a variant of how Epaminondas shattered the myth of Spartan invincibility at Leuctra: Extremely concentrated force at a precise location on the battlefield,” he posted.

There was no immediate comment from Mr Trump or the White House on Mr Musk’s announcement.The feud with Mr Trump, often described as one between the world’s richest man and the world’s most powerful, has led to several precipitous falls in Tesla’s share price.

The stock soared after Mr Trump’s November re-election and hit a high of more than $US488 ($744) in December, before losing more than half of its value in April and closing last week out at $US315.35.

Despite Mr Musk’s deep pockets, breaking the Republican-Democratic duopoly will be a tall order, given that it has dominated American political life for more than 160 years, while Mr Trump’s approval ratings in polls in his second term have generally held firm above 40 per cent, despite often divisive policies.