President Donald Trump slammed the lawyer Michael Avenatti in a post on Twitter Wednesday after a third woman, who Avenatti represents, came forward with sexual misconduct allegations against Supreme Court nominee Brett Kavanaugh.

"Avenatti is a third rate lawyer who is good at making false accusations, like he did on me and like he is now doing on Judge Brett Kavanaugh," Trump wrote. "He is just looking for attention and doesn't want people to look at his past record and relationships - a total low-life!"

Read more: The full sworn statement from Julie Swetnick

Avenatti, who is representing the porn star Stormy Daniels in a legal battle against the president, and has said he is exploring a bid to challenge Trump in the 2020 presidential race, released an affidavit from his client Julie Swetnick earlier in the day. Swetnick alleged in the sworn statement that Kavanaugh and others spiked girls' drinks in high school in order to make it easier for them to be gang raped.

In response to the president's tweet, Avenatti responded almost immediately: "Let's go," he said.

Avenatti tweet

Kavanaugh has flatly denied all the allegations against him.

In a statement Wednesday, Kavanaugh called the latest accusation "ridiculous and from the Twilight Zone."

"I don't know who this is and this never happened," he said.

Sen. Lindsey Graham R-S.C., a member of the Senate committee reviewing Kavanaugh's nomination, also lashed out against Avenatti Wednesday.

"The lawyer to porn stars has just taken this debacle to an even lower level," Graham said in a statement. "I hope people will be highly suspicious of this allegation presented by Michael Avenatti."

Avenatti had been teasing the new allegation for days, warning the president and his allies to avoid attempts at discrediting his client.

"Be very, very careful if you launch some smear campaign against my client," Avenatti said on CNN Monday, "because you will ultimately be shown to be a fraud."

-- CNBC's Kevin Breuninger contributed to this report.