(CNN) President Donald Trump started his Sunday morning by lashing out at special counsel Robert Mueller's team , former FBI Deputy Director Andrew McCabe, and former FBI Director James Comey.

Just a day after news that Mueller had interviewed McCabe and asked him about Comey's firing , Trump attacked the special counsel's team, seeming to suggest it has a partisan bias.

"Why does the Mueller team have 13 hardened Democrats, some big Crooked Hillary supporters, and Zero Republicans? Another Dem recently added ... does anyone think this is fair? And yet, there is NO COLLUSION!," Trump wrote on Twitter.

Trump's criticism of Mueller, a Republican, appears to be the first time he has attacked the special counsel by name on Twitter, according to an archive of Trump's tweets. However, CNN, citing a person familiar with the matter, reported in January that Trump called for Mueller's firing last June; The New York Times was first to report that incident, citing four people told of the matter; Trump has denied calling for the special counsel's ouster.

Trump's attack on Mueller came after his personal lawyer, John Dowd, called for an end to the special counsel's probe into Russian election meddling.

"I pray that Acting Attorney General Rosenstein will follow the brilliant and courageous example of the FBI Office of Professional Responsibility and Attorney General Jeff Sessions and bring an end to alleged Russia collusion investigation manufactured by McCabe's boss James Comey based upon a fraudulent and corrupt dossier," Dowd told CNN in a statement, reacting to the news of McCabe's firing on Friday night by Attorney General Jeff Sessions.

Dowd told CNN he was speaking on his own behalf, although he had earlier told the Daily Beast, which first reported the statement, that he was speaking on behalf of the President. Dowd's comment wasn't authorized by the President, a person close to Trump told CNN.

White House special counsel Ty Cobb emphasized in a statement Sunday night that Trump is not considering firing Mueller.

"In response to media speculation and related questions being posed to the administration, the White House yet again confirms that the President is not considering or discussing the firing of the special counsel, Robert Mueller," Cobb said.

The President also called into question news that McCabe had written memos about their interactions. A source told CNN Saturday that Mueller's team has those memos.

"Spent very little time with Andrew McCabe, but he never took notes when he was with me," Trump tweeted. "I don't believe he made memos except to help his own agenda, probably at a later date. Same with lying James Comey. Can we call them Fake Memos?"

McCabe's attorney, Michael Bromwich, issued a statement on Twitter Sunday afternoon in response to the President, saying the tweets prove Trump "corrupted the entire process that led to Mr. McCabe's termination and has rendered it illegitimate."

"We will not be responding to each childish, defamatory, disgusting & false tweet by the President. The whole truth will come out in due course," he wrote.

McCabe told CNN that he had three in-person interactions and one phone call with Trump.

White House legislative affairs director Marc Short downplayed Trump and Dowd's comments in an interview with moderator Margaret Brennan on CBS's "Face the Nation," saying neither Trump nor anyone else in the White House is suggesting not cooperating fully with the Mueller investigation.

"Everyone in the White House has cooperated on this, and what I said is that we have cooperated in every single way, every single paper they've asked for, every single interview," Short said. "And I think the reality, Margaret, is that yes, there's a growing frustration that after more than a year and millions and millions of dollars spent on this, there remains no evidence of collusion with Russia."

Trump's attacks on the special counsel team reinforced demands by Democrats to protect Mueller's investigation. Senate Minority Leader Chuck Schumer and Sen. Mark Warner, the vice chairman of the Senate Intelligence Committee, issued calls to defend the probe following Dowd's comments.

Schumer said in a statement Sunday morning: "The President is floating trial balloons about derailing the Mueller investigation. Our Republican colleagues, particularly the leadership, have an obligation to our country to stand up now and make it clear that firing Mueller is a red line for our democracy that cannot be crossed."