Lawyers for Julian Assange on Tuesday made a last-ditch effort to prevent his extradition to the United States after fighting it for more than a decade.

Facing espionage charges, the WikiLeaks founder has already seen several attempts to fight extradition rejected. Addressing the Royal Courts of Justice in London, Assange’s legal team sought a new appeal hearing as hundreds of supporters rallied outside with “Free Julian Assange” signs.

His lawyers contend that his actions uncovered significant criminal misconduct by U.S. authorities and that their client risks “flagrant denial of justice” if forced to the U.S.

“He is being prosecuted for engaging in ordinary journalistic practice of obtaining and publishing classified information, information that is both true and of obvious and important public interest,” Edward Fitzgerald, Assange’s lead lawyer, told the court.

Assange is facing 17 charges of espionage, along with one charge of computer misuse over publication of classified U.S. documents on the WikiLeaks website. U.S. prosecutors also say Assange helped U.S. Army intelligence analyst Chelsea Manning steal files that were later published and put lives at risk.

James Lewis, the lawyer representing the U.S., emphasized that Assange’s actions posed a significant threat to the strategic and national security interests of the U.S. and put individuals named in the documents — including Iraqis and Afghans who had helped the U.S. — at risk of “serious physical harm.”

If the British court rules against Assange, his lawyers have vowed to challenge his extradition in the European Court of Human Rights in Strasbourg, France. Supporters, however, worry that he could be sent to the U.S. before that can happen.

The British government has already signed an extradition order, despite previously rejecting the U.S. extradition request in 2021 on the grounds that Assange was likely to kill himself if held in the harsh U.S. prison system.

Despite being granted permission to attend the trial Tuesday from Belmarsh Prison outside London where he has been detained for five years, Assange was notably absent, opting not to appear.

His legal representative highlighted his absence, citing his current state of being “unwell” and acknowledging a decline in his health during his prolonged incarceration.

According to Assange’s legal team, if convicted, he could potentially face up to 175 years in prison, although U.S. authorities have indicated the likelihood of a considerably shorter term.

Some information is from The Associated Press.