Special counsel Jack Smith said his team “stood up for the rule of law” as it investigated President-elect Donald Trump’s efforts to overturn the results of the 2020 US election, writing in a much-anticipated report that was released on Tuesday night (AEDT) that he stands fully behind his decision to bring criminal charges he believes would have resulted in a conviction had voters not returned Trump to the White House.

“The throughline of all of Mr Trump’s criminal efforts was deceit — knowingly false claims of election fraud — and the evidence shows that Mr Trump used these lies as a weapon to defeat a federal government function foundational to the United States’ democratic process,” the report states.

The report, arriving just days before Trump is to return to office on January 20, focuses fresh attention on his frantic but failed effort to cling to power in 2020.

With the prosecution foreclosed thanks to Trump’s election victory, the document is expected to be the final Justice Department chronicle of a dark chapter in American history that threatened to disrupt the peaceful transfer of power, a bedrock of democracy for centuries, and complements already released indictments and reports.

Trump responded early on Tuesday with a post on his Truth Social platform, claiming he was “totally innocent” and calling Smith “a lamebrain prosecutor who was unable to get his case tried before the Election.”

He added, “THE VOTERS HAVE SPOKEN!!!”

Trump had been indicted in August 2023 on charges of working to overturn the election, but the case was delayed by appeals and ultimately significantly narrowed by a conservative-majority Supreme Court that held for the first time that former presidents enjoy sweeping immunity from criminal prosecution for official acts.

Though Smith sought to salvage the indictment, the team dismissed it entirely in November because of longstanding Justice Department policy that says sitting presidents cannot face federal prosecution.

“The Department’s view that the Constitution prohibits the continued indictment and prosecution of a President is categorical and does not turn on the gravity of the crimes charged, the strength of the Government’s proof, or the merits of the prosecution, which the Office stands fully behind,” the report states.

“Indeed, but for Mr Trump’s election and imminent return to the Presidency, the Office assessed that the admissible evidence was sufficient to obtain and sustain a conviction at trial.”

The Justice Department transmitted the report to Congress early on Tuesday (US time) after a judge refused a defence effort to block its release.

A separate volume of the report focused on Trump’s hoarding of classified documents at Mar-a-Lago, actions that formed the basis of a separate indictment against Trump, will remain under wraps for now.

Though most of the details of Trump’s efforts to undo the election are already well established, the document includes for the first time a detailed assessment from Smith about his investigation, as well as a defence by Smith against criticism by Trump and his allies that the inquiry was politicised or that he worked in collaboration with the White House — an assessment he called “laughable”.

“While we were not able to bring the cases we charged to trial, I believe the fact that our team stood up for the rule of law matters,” Smith wrote in a letter to Attorney General Merrick Garland attached to the report.

“I believe the example our team set for others to fight for justice without regard for the personal costs matters.”

The special counsel also laid out the challenges it faced in its investigation, including Trump’s assertion of executive privilege to try to block witnesses from providing evidence, which forced prosecutors into sealed court battles before the case was charged.

Another “significant challenge” was Trump’s “ability and willingness to use his influence and following on social media to target witnesses, courts, prosecutors,” which led prosecutors to seek a gag order to protect potential witnesses from harassment, Smith wrote.

“Mr Trump’s resort to intimidation and harassment during the investigation was not new, as demonstrated by his actions during the charged conspiracies,” Smith wrote.

“A fundamental component of Mr Trump’s conduct underlying the charges in the election case was his pattern of using social media — at the time, Twitter — to publicly attack and seek to influence state and federal officials, judges, and election workers who refused to support false claims that the election had been stolen or who otherwise resisted complicity in Mr Trump’s scheme,” he added.

Smith also for the first time explained the thought process behind his team’s prosecution decisions, writing that his office decided not to charge Trump with incitement in part because of free speech concerns, or with insurrection because he was the sitting president at the time and there was doubt about proceeding to trial with the offence — of which there was no record of having been prosecuted before.