U.S. federal prosecutors moved Monday to dismiss the criminal charges against U.S. president-elect Donald Trump that accused him of plotting to overturn the 2020 election and to abandon the classified documents case against him, citing longstanding U.S. Justice Department policy that says sitting presidents cannot face criminal prosecution.

The decision by special counsel Jack Smith, who had fiercely sought to hold Trump criminally accountable for his efforts to subvert the 2020 election, represented the end of the federal effort against the former president following his election victory this month, despite the election-related cases and multiple other unrelated criminal charges against him.

The decision, revealed in court filings, also amounts to a predictable but nonetheless stunning conclusion to criminal cases that had been seen as the most perilous of the multiple legal threats Trump has faced. It reflects the practical consequences of Trump's victory, ensuring he enters office free from scrutiny over his hoarding of top-secret documents and his efforts to overturn the 2020 presidential election he lost to Democrat Joe Biden.

Smith's team emphasized that the move to abandon the prosecutions, in federal courts in Washington and Florida, was not a reflection of their view on the merits of the cases but rather a reflection of their commitment to longstanding department policy.

"That prohibition 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 Government stands fully behind," the prosecutors wrote in Monday's court filing in the election interference case.

Trump victory forced issue of how to proceed

The decision was expected after Smith's team began assessing how to wind down both the 2020 election interference case and the separate classified documents case in the wake of Trump's victory over U.S. Vice-President Kamala Harris.

The Justice Department believes Trump can no longer be tried in accordance with longstanding policy that says sitting presidents cannot be prosecuted.

Trump has cast both cases as politically motivated, and had vowed to fire Smith as soon as he takes office in January.

The 2020 election case brought last year was once seen as one of the most serious legal threats facing the Republican. But it quickly stalled amid legal battles over Trump's sweeping claims of immunity from prosecution for his actions while he was in the White House.

The U.S. Supreme Court in July ruled for the first time that former presidents have broad immunity from prosecution, and sent the case back to U.S. District Judge Tanya Chutkan to determine which allegations in the indictment, if any, could proceed to trial.

The case was just beginning to pick up steam again in the trial court in the weeks leading up to this year's election. Smith's team in October filed a lengthy brief laying out new evidence they planned to use against Trump at trial, accusing him of "resorting to crimes" in an increasingly desperate effort to overturn the will of voters after he lost to Biden.