US Department of Justice Special Counsel Jack Smith has appealed to a federal court to resurrect the case against former president Donald Trump for allegedly mishandling classified government documents found at his Florida home in 2021.

The case was dismissed in July by Judge Aileen Cannon in Florida, a Trump appointee, who ruled that the mere existence of special counsels violated the US Constitution.

In his request on Monday, Mr Smith wrote that the judge's view "deviated" from legal precedent and "took an inadequate account" of the history of legally-appointed special counsels.

Trump's legal team has until 26 September to submit a response to Mr Smith's arguments.

Trump had pleaded not guilty to several felony charges in the now-dismissed case, including wilful retention of national defence information.

The 37-count indictment accused Trump of keeping files at his Florida estate and lying to investigators. It also alleged he tried to obstruct the investigation into his handling of the documents.

He was charged alongside aide Walt Nauta and former employee Carlos de Oliveira, who had also pleaded not guilty.

Mr Smith's request on Monday defended the appointment of special counsels to a federal appeals court in Atlanta. The filing refers to "Congress's endorsement of that practice through appropriations and other legislation".

"The attorney general validly appointed the special counsel, who is also properly funded," Mr Smith's team said.

"In ruling otherwise, the district court deviated from binding Supreme Court precedent, misconstrued the statutes that authorized the special counsel's appointment, and took inadequate account of the longstanding history of Attorney General appointments of special counsels."

It noted the landmark 1974 case against former President Richard Nixon, arguing that it proves that the attorney general has "appointment authority" for special counsels.

"Nixon conclusively defeats the defendants' challenge to the Special Counsel's appointment, as every other court to have considered the issue has found," the filing argued.

"Congress has bestowed on the Attorney General, like the heads of many Executive Departments, broad authority to structure the agency he leads to carry out the responsibilities imposed on him by law," Mr Smith's prosecutors wrote.

The case was one of four criminal trials Trump was facing. Regardless of how the classified documents case proceeds, it is extremely unlikely to go to trial ahead of the presidential election in November.

If Trump wins the election, experts predict that he will order the justice department to dismiss the cases against him.

A special counsel has the powers of a US attorney - meaning they can subpoena records and bring criminal charges. They are appointed by attorneys general to facilitate an independent, impartial investigation.

They can also prosecute anyone who interferes in their investigation through crimes including perjury, obstruction of justice, destruction of evidence, and intimidation of witnesses.

They are not supervised on a day-to-day basis by the justice department, which provides staff to special counsel's office.

Mr Trump is not the only notable figure being investigated by a special counsel.

President Joe Biden's son, Hunter, is also being prosecuted for gun and tax crimes by a special counsel appointed by Attorney General Merrick Garland.

Mr Garland appointed Mr Smith in 2022 to oversee two federal investigations into Mr Trump - the classified documents case and another case arguing that Trump attempted to interfere in the result of the 2020 election.

Both cases face uncertain outcomes after the Supreme Court ruled last month that presidents are legally immune from certain actions they take while in office.