Lawyers for former President Donald J. Trump asked a judge on Thursday to throw out a federal indictment accusing him of conspiring to overturn the 2020 election and claimed that because the charges relate to actions he took as president, he should be “absolutely immune from prosecution.”

The request to dismiss the election interference indictment, which came in a 52-page briefing filed in Federal District Court in Washington, was breathtaking in its scope. It argued that Mr. Trump could not be held accountable in court for any actions he took as president, even after a grand jury had returned criminal charges against him.

While the Justice Department has long maintained a policy that sitting presidents cannot be indicted, Mr. Trump’s bid to claim total immunity from prosecution was a remarkable attempt to extend the law in his favor.

His motion to dismiss was certain to result in a pitched legal battle with prosecutors in the office of the special counsel, Jack Smith, if only because the idea that a president cannot be prosecuted for actions undertaken in his official capacity as commander in chief has never before been tested.

The motion, which will be considered by Judge Tanya S. Chutkan, was also the first — but likely not the last — attempt by Mr. Trump’s lawyers to attack the charges in the election interference case directly.

Until now, the lawyers have largely waged a series of unsuccessful procedural battles, seeking, and failing, to push back the trial until 2026 and to disqualify Judge Chutkan.

In his filing, John F. Lauro, a lawyer for Mr. Trump, immediately sought to reframe the core of Mr. Smith’s case. He argued that the former president’s repeated lies that widespread fraud had marred the vote count and other steps he took to subvert the normal course of the democratic process were, in fact, “efforts to ensure election integrity.”

Moreover, those efforts, Mr. Lauro argued, were “at the heart of” Mr. Trump’s “official responsibilities as president” and so should not be subject to criminal charges.

“Here, 234 years of unbroken historical practice — from 1789 until 2023 — provide compelling evidence that the power to indict a former president for his official acts does not exist,” Mr. Lauro wrote. “No prosecutor, whether state, local, or federal, has this authority; and none has sought to exercise it until now.”