WASHINGTON (TNND) — Just as Senate Republicans began to work on their version the “One Big Beautiful Bill” to usher in key parts of President Donald Trump’s agenda, the man once considered Trump’s right-hand man and self-proclaimed “first buddy” issued a post on social media that threatened to derail–or at least discredit–the legislation altogether.

“I’m sorry, but I just can’t stand it anymore. 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,” Elon Musk posted on X Tuesday afternoon.

“It will massively increase the already gigantic budget deficit to $2.5 trillion (!!!) and burden American citizens with crushingly unsustainable debt,” Musk, who stepped away from his White House position last week, said in another post minutes later.

The posts came as White House Press Secretary Karoline Leavitt was briefing members of the press.

“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,” Leavitt said.

House Speaker Mike Johnson called Musk’s comments “very disappointing” and “very surprising.”

“With all due respect, my friend Elon is terribly wrong about the One Big Beautiful Bill. We had a long conversation yesterday, he and I spoke for I think more than 20 minutes on the telephone, and I extolled all the virtues of the bill, and he seemed to understand that,” Johnson said.

The speaker disputed Musk’s assertion and assessments from the nonpartisan Congressional Budget Office that the legislation, in its current form, could add trillions to the national debt over time.

“Elon is missing it, OK? And it’s not personal. I know that the (electric vehicle) mandate is very important to him. That is going away because the government should not be subsidizing these things. It’s part of the Green New Deal, and I know that has an effect on his business, and I lament that,” Johnson said.

When asked if he thinks Musk’s interest in Tesla is driving his public comments on the legislation, Johnson said, “I’m gonna let others draw their own conclusions about that.”

Musk did get some immediate support from GOP budget hawks.

Rep. Thomas Massie, R-Ky., replying to Musk’s post, wrote, “He’s right.” Musk also got a nod from Sen. Mike Lee, R-Utah.

“Federal spending has become excessive(.) The resulting inflation harms Americans(.) And weaponizes government(.) The Senate can make this bill better(.) It must now do so,” Lee said in a post.

During a weekly leadership press conference, Senate Majority Leader John Thune said of Musk’s comment, “We have a difference of opinion. He’s entitled to that opinion. We’re gonna proceed full speed ahead.”