WikiLeaks founder Julian Assange was absent from a London court due to illness Tuesday, as his lawyers launched a likely last bid to appeal against his extradition to the United States to face espionage charges.

Washington indicted the Australian multiple times between 2018 and 2020 over WikiLeaks' publication of secret military and diplomatic files on the U.S.-led wars in Iraq and Afghanistan.

On the first of two days of evidence before two High Court judges, the 52-year-old's leading lawyer said previous rulings contained "errors of law" and that the U.S. charges against him were "political".