Peter Navarro, the Trump administration's trade adviser, made a last-minute plea to the Supreme Court to keep him out of prison on a contempt of Congress conviction, according to reports. 

Lawyers for Navarro, who is due to report to federal prison in Miami next Tuesday, filed the emergency appeal on Friday.

He was convicted and sentenced to prison in January for refusing to release documents or testify to Congress in its investigation into the Jan. 6, 2021 riot at the U.S. Capitol that saw mobs of then-President Donald Trump's supporters try to derail the results of the 2020 election, the Associated Press reported.

Navarro has insisted that he was unable to cooperate with the investigation because he was barred from doing so after Trump invoked executive privilege.

The judge in his trial rejected that argument, saying there's no evidence Trump had invoked it.

Navarro turned to the Supreme Court after a federal appeals court denied his appeal to postpone his four-month sentence.

"For the first time in our nation's history, a senior presidential advisor has been convicted of contempt of congress after asserting executive privilege over a congressional subpoena," Navarro attorneys Stan Brand and Stanley Woodward wrote in the high court filing, Politico reported.

"The prosecution of a senior presidential advisor asserting executive privilege conflicts with the constitutional independence required by the doctrine of separation of powers," they said.