A Florida judge has just dismissed the Justice Department's classified documents case against Donald Trump in a huge victory for the former president just days after a gunman attempted to assassinate him.

Judge Aileen Cannon has granted Trump's motion to dismiss the federal case on the basis that the Justice Department's appointment of Special Prosecutor Jack Smith violates the Appointments Clause of the US Constitution.

Trump pleaded not guilty to several charges in the case over his handling of classified documents, including wilful retention of national defence information.

Dozens of classified files were found in Trump's Mar-a-Lago resort in Florida, including in a shower and storage room, after Trump left the White House in 2021.

"The Court is convinced that Special Counsel’s Smith’s prosecution of this action breaches two structural cornerstones of our constitutional scheme—the role of Congress in the appointment of constitutional officers, and the role of Congress in authorizing expenditures by law,” Cannon concluded in her 93-page order.

The former president faced 40 felony counts over his alleged mishandling of classified documents.

Judge Cannon said in her ruling that this decisions applies to this case and not a second one overseen by Mr Smith over alleged efforts to overturn the 2020 election.

The Trump-appointed Florida judge had recently indefinitely postponed the federal classified documents trial, saying there were significant questions over trial evidence.

Mr Smith will now be able to appeal Monday's ruling and ask for a new judge to be assigned to the case.

He has yet to publicly commented on Judge Cannon's ruling.

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