Julian Assange’s legal team returned to London’s High Court on Tuesday to fight for what could become his final attempt at avoiding extradition to the United States, where he is facing life in prison if convicted on espionage charges.

After a years-long battle, the 52-year-old WikiLeaks founder is down to his only remaining legal avenue in the British justice system and now just two UK High Court judges stand between him and a possible flight across the Atlantic.

The two-day hearing will examine whether the embattled Australian should be granted leave to appeal a 2022 extradition decision made by former UK Home Secretary Priti Patel. If the court’s decision goes against Assange, he must be extradited within 28 days. However, his legal team is expected to apply to the European Court of Human Rights for an intervention to ground the flight through a rule 39 order.

Assange is wanted by US authorities on 18 criminal charges relating to his organization’s dissemination of classified material and diplomatic cables in 2010 and 2011.

Each of those counts carries a potential sentence of 10 years, meaning that if convicted, Assange could be sentenced to up to 175 years in prison.

Tuesday’s hearing is the latest stage in a convoluted journey that has left Assange incarcerated at Belmarsh, a high-security prison in the south-east of the British capital, years after an undignified eviction from London’s Ecuadorian embassy.