Lawyer Michael Avenatti tweeted Thursday that he is ready to cooperate with a Justice Department investigation into himself and client Julie Swetnick as soon as "tonight."

His tweet, directed at Senate Judiciary Committee Chairman Chuck Grassley Charles (Chuck) Ernest GrassleyGOP lawmakers distance themselves from Trump comments on transfer of power The Hill's 12:30 Report: Ginsburg lies in repose Top GOP senators say Hunter Biden's work 'cast a shadow' over Obama Ukraine policy MORE (R-Iowa), came hours after Grassley announced he is referring Swetnick and Avenatti to the Justice Department for a potential criminal investigation into whether they made false statements to Congress about Supreme Court Justice Brett Kavanaugh Brett Michael KavanaughSenate GOP set to vote on Trump's Supreme Court pick before election Conservative groups unleash ad blitz in support of Barrett's nomination Two Judiciary Democrats say they will not meet with Trump's Supreme Court pick MORE.

ADVERTISEMENT "@ChuckGrassley, let’s start the investigation tonight," Avenatti tweeted on Thursday evening. "I will make my client available for a sworn interview and you can make Judge Kavanaugh available for a sworn interview." "We also have 9 other witnesses we want interviewed and specific documents we want requested," he added. "Let’s go."

.@ChuckGrassley - let’s start the investigation tonight. I will make my client available for a sworn interview and you can make Judge Kavanaugh available for a sworn interview. We also have 9 other witnesses we want interviewed and specific documents we want requested. Let’s go. — Michael Avenatti (@MichaelAvenatti) October 25, 2018

Avenatti represents Swetnick, who last month made a series of shocking allegations against Kavanaugh during his confirmation process.

Swetnick in a sworn affidavit claimed that Kavanaugh in the 1980s attended parties where women were gang-raped. Swetnick said Kavanaugh engaged in a pattern of exploitative and non-consensual behavior with girls at those high school parties.

Multiple news outlets were unable to corroborate her allegations, and they were treated more gingerly than the sexual allegations against Kavanaugh from two other women.

Grassley on Thursday said that in addition to making false statements, he is asking for the Justice Department to look into whether the two sought to obstruct his panel's investigation of the allegations against Kavanaugh.

"The law prohibits such false statements to Congress and obstruction of congressional committee investigations," Grassley wrote. "For the law to work, we can’t just brush aside potential violations. I don’t take lightly making a referral of this nature, but ignoring this behavior will just invite more of it in the future."