Saying he recently gained access to a hard drive containing 14 millions files that could have "significant value" to congressional investigators, attorneys for Michael Cohen urged authorities to reduce or at least delay his 3-year prison sentence.

In a letter to Congress Thursday, Cohen's lawyers said their client has cooperated with both federal investigators and lawmakers. They wrote he would have a difficult time gathering the documents and participating in the interviews investigators have requested before he is set to start his prison sentence next month. They said the president's former attorney needs to be "readily accessible and immediately available" for congressional investigators because he recently was able to access the hard drive with "important documents."

"Said drive contains over 14 million files, which consist of all e-mails, voice recordings, images, and attachments from Mr. Cohen's computers and phones," attorneys Lanny Davis, Michael Monico and Carly Chocron wrote. "To date, Mr. Cohen has located several documents that we believe have significant value to the various congressional oversight and investigation committees."

Cohen's lawyers said their client has only been able to review "less than 1 percent" of the files and needs more time to analyze all the information. They noted their letter was only sent to congressional Democrats because they were not sure Republicans were "interested" in Cohen's new information, saying GOP lawmakers did not ask "substantive" questions and attacked their client during his congressional testimony in February. The lawyers added, however, that they would send the letter and other materials to Republicans if requested.

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Asking them to consider the "total picture" of Cohen's cooperation with authorities, his lawyers urged prosecutors at the Southern District of New York to grant their client a "reduced term" and to postpone his incarceration for "about four weeks."

"It is a fact that Mr. Cohen remains the only member of the Trump Organization, including Mr. Trump himself, who has been prosecuted and who is going to prison for conduct almost all of which was for the benefit of Mr. Trump personally and indeed directed by him," the lawyers wrote. "In our opinion, there is something unjust here."

Along being sentenced to two months in prison after pleading guilty to lying to Congress, Cohen was also given a 3-year sentence for violating campaign finance law "in coordination with and at the direction" of the president by paying two women to remain silent during the 2016 campaign about their alleged affairs with Mr. Trump.

In Thursday's letter, Cohen lawyers said their client's sentence was "disproportionate."

"It is our professional opinion that the length of the sentence to which Mr. Cohen was subjected is, most respectfully, disproportionate given the particular facts and circumstances underlying each of the crimes to which Mr. Cohen pled guilty," they wrote.