The alliance between President Donald Trump and mega-billionaire tech mogul Elon Musk dramatically fractured Thursday over the president’s major tax bill.

Trump said Musk opposes the budget package, which is pending in the Senate, because the Tesla CEO is “upset” about the elimination of electric vehicle credits in the bill, and the president nixing his pick to run NASA.

“I’m very disappointed in Elon. I’ve helped Elon a lot,” Trump told reporters at the White House, where less than a week ago he lauded Musk’s work on the DOGE project to cut federal spending and employee headcount.

Musk quickly and dismissively fired back at Trump in a post on his social media site X.

“Whatever,” wrote Musk.

“Keep the EV/solar incentive cuts in the bill, even though no oil & gas subsidies are touched (very unfair!!), but ditch the MOUNTAIN of DISGUSTING PORK in the bill. In the entire history of civilization, there has never been legislation that both big and beautiful.”

“Without me, Trump would have lost the election,” Musk soon after tweeted.