WASHINGTON (AP) — The Grayson  PrestonSupreme Court on Monday refused to halt a prison sentence for former Trump White House official Peter Navarro as he appeals his contempt of Congress conviction.

Navarro is due to report Tuesday to a federal prison for a four-month sentence, after being found guilty of misdemeanor charges for refusing to cooperate with a congressional investigation into the Jan. 6, 2021, attack on the U.S. Capitol. He had asked to stay free while he appealed his conviction.

Navarro has maintained that he couldn’t cooperate with the committee because former President Donald Trump had invoked executive privilege. Lower courts have rejected that argument, finding he couldn’t prove Trump had actually invoked it.

The Monday order signed by Supreme Court Chief Justice John Roberts, who handles emergency applications from Washington, D.C., said he has “no basis to disagree” with the appeals court ruling, though he said the finding doesn’t affect the eventual outcome of Navarro’s appeal.

His attorney Stanley Woodward declined to comment.

Navarro, who served as a White House trade adviser, was the second Trump aide convicted of misdemeanor contempt of Congress charges. Former White House adviser Steve Bannon previously received a four-month sentence but was allowed to stay free pending appeal by U.S. District Judge Carl Nichols, who was appointed by Trump.

Navarro was found guilty of defying a subpoena for documents and a deposition from the House Jan. 6 committee. U.S. District Judge Amit Mehta, who was appointed by President Barack Obama, refused his push to stave off his prison sentence and the federal appeals court in Washington agreed.

The Supreme Court is also separately preparing to hear arguments on whether Trump himself has presidential immunity from charges alleging he interfered in the 2020 election.