"The fish stinks from the head down. But I can tell you two fish that don't stink, and that's me and the President," he said, casting doubt on the rest of the staff and their motives.
It was the latest salvo in his hunt for the source of White House leaks. It is a cause close to the President's heart and Scaramucci has made it clear that he answers only to Trump.
He appeared to point the finger at Priebus, first in a rapidly deleted Tweet on Thursday. Then he further fanned the flames on CNN yesterday, challenging Priebus to deny he was the source.
"When I put out a tweet and I put Reince's name in a tweet, they're all making the assumption that it's him because journalists know who the leakers are," he said during the unscheduled 30-minute interview.
"So if Reince wants to explain he's not a leaker, let him do that. But let me tell you about myself. I'm a straight shooter and I'll go right to the heart of the matter."
His relationship with Priebus was already fraught before he was appointed last Saturday. The chief of staff was among the voices urging Trump not to bring the Mooch, as he is nicknamed, into the White House.
The latest spat was sparked by publication of an official document detailing Scaramucci's finances, even though it is available to anyone who asks. On Thursday, Scaramucci was further angered when a reporter obtained details of a White House dinner. He telephoned Ryan Lizza of the New Yorker to demand how he found out he had dined with the President, first lady, a Fox News host and one of the network's former executives.
Lizza promptly published the whole extraordinary exchange. He described how Scaramucci threatened to sack everyone in the communications department if he did not reveal the source of his information. He also claimed Priebus would soon be forced out.
"They'll all be fired by me," he said. "I fired one guy the other day. I have three to four people I'll fire tomorrow. I'll get to the person who leaked that to you. Reince Priebus - if you want to leak something - he'll be asked to resign very shortly."
He went on to reportedly describe Priebus as a "f****** paranoid schizophrenic" and described Steve Bannon, Trump's chief strategist, in profane terms.
"I'm not Steve Bannon, I'm not trying to suck my own ****," he said. "I'm not trying to build my own brand off the ******* strength of the president. I'm here to serve the country."
Bannon "declined to comment".
Scaramucci did not apologise for the tirade, but said he would try to clean up his language in the future and that: "I made a mistake in trusting in a reporter. It won't happen again."
White House spokeswoman Sarah Huckabee Sanders said Scaramucci "used some colourful language - I don't think he will again."
The president's senior counsellor, Kellyanne Conway, had earlier speculated in a Fox News interview that unnamed forces were out to get Scaramucci, saying: "Somebody is trying to get in his way and scare him off."
Healthcare repeal bid fails
In a stinging blow to President Donald Trump, Senate Republicans failed yesterday to dismantle Obamacare, falling short on a major campaign promise and perhaps ending a seven-year quest by their party to gut the healthcare law. Three Republican senators, John McCain, Susan Collins and Lisa Murkowski, crossed party lines to join Democrats in a dramatic 49-to-51 vote to reject a "skinny repeal" bill that would have killed some parts of Obamacare. The setback leaves Trump without a major legislative win after more than six months in power.
The US House yesterday passed a $788 billion ($1.05 trillion) spending bill that combines a US$1.6b down-payment for Trump's controversial border wall with Mexico with a whopping budget increase for the Pentagon. Challenging hurdles remain in front of the measure, however, which will meet with more powerful Democratic opposition in the Senate. Trump promised at nearly every rally and campaign event that Mexico would pay for the wall. Mexico said no, and US taxpayers will have to provide the money.
The Senate's decisive vote to approve a new package of stiff financial sanctions against Russia, Iran and North Korea sends the popular bill to Trump, who will be under pressure to sign it after weeks of intense negotiations. The Senate passed the bill, 98-2, two days after the House pushed the measure through by an overwhelming margin, 419-3.