FILE - In this Jan. 10, 2017 file photo, then-FBI Director James Comey testifies on Capitol Hill in Washington. Lawyers for President Donald Trump unleashed a blistering attack on Comey in a confidential memo last year addressed to special counsel Robert Mueller, casting him as ÒMachiavellian,Ó dishonest, self-serving and Òunbounded by law and regulation.Ó The June 27, 2017 letter, obtained by The Associated Press, underscores the Trump legal teamÕs intense effort over the last year to undermine the credibility of a law enforcement leader it sees as a critical witness against the president. (AP Photo/Cliff Owen, File)

By ERIC TUCKER and CHAD DAY

Associated Press

WASHINGTON — Lawyers for President Donald Trump unleashed a blistering attack on former FBI Director James Comey in a confidential memo last year to the special counsel, casting him as “Machiavellian,” dishonest and “unbounded by law and regulation” as they sought to undermine the credibility of a law enforcement leader they see as a critical witness against the president.

The letter, obtained by The Associated Press, underscores the intense effort by Trump’s legal team over the last year to tarnish Comey’s reputation and pit the president’s word against that of the former FBI director. Comey’s firing in May 2017 helped set in motion the appointment of special counsel Robert Mueller, and one-on-one conversations with Trump that Comey documented in a series of memos helped form the basis of Mueller’s inquiry into whether the president obstructed justice.

The June 27, 2017, letter was written by Marc Kasowitz, then the president’s lead lawyer, as Mueller and his team were in the early stages of their investigation into Trump associates and as they had begun examining whether the president, by firing Comey, had sought to stymie an FBI investigation into the Trump campaign’s ties to Russia. The White House initially pointed as justification for the firing to a Justice Department memo that faulted Comey for his handling of the Hillary Clinton email investigation, though Trump later said that “this Russia thing” was on his mind when he made the move.

It’s not clear to what extent, if any, the attacks on Comey have resonated with Mueller’s team, which is broadly investigating Russian meddling in the 2016 presidential election and continues to seek an interview with the president to assess whether he had a corrupt intent when he fired the FBI director. And even in the face of withering criticism, Comey has been largely consistent in his telling of his interactions with Trump in his memos, his book and numerous press interviews he’s given in recent months.

The 13-page document provides a window into the formation of a legal strategy that remains in use today by Trump’s lawyers — to discredit Comey’s value as a witness. It could have new relevance in the aftermath of a Justice Department inspector general report that criticized Comey for departing from established protocol in the Clinton investigation.

The letter aims to identify for Mueller what the lawyers believe are grievous errors both in how Comey handled the Clinton investigation and in his early, and limited, encounters with the president. In it, Kasowitz argues that Comey cannot be trusted as a witness because he repeatedly embellished his testimony before Congress, put his “own personal interests and emotions” above FBI protocol and left a cloud of undue suspicion above the president’s head.