LONDON — WikiLeaks founder Julian Assange faces a hearing Monday in the High Court in London that could end with him being sent to the U.S. to face espionage charges, or provide him another chance to appeal his extradition.

The outcome will depend on how much weight judges give to assurances U.S. officials have provided that Assange’s rights won’t be trampled if he goes on trial.

In March, two judges rejected the bulk of Assange’s arguments but said he could take his case to the Court of Appeal unless the U.S. guaranteed he would not face the death penalty if extradited and would have the same free speech protections as a U.S. citizen.

The court said that if Assange, who is an Australian citizen, couldn’t rely on the First Amendment then it was arguable his extradition would be incompatible with the European Convention on Human Rights, which also provides free speech and press protections.

The U.S. has provided those reassurances, though Assange’s legal team and supporters argue they are not good enough to rely on to send him to the U.S. federal court system.

The U.S., for example, said Assange could seek to rely on the rights and protections of the First Amendment but that a decision on that would ultimately be up to a judge. In the past, the U.S. said it would argue at trial that he was not entitled to the constitutional protection because he’s not a U.S. citizen.

“The U.S. has limited itself to blatant weasel words claiming that Julian can ‘seek to raise’ the First Amendment if extradited,” his wife, Stella Assange, said. “The diplomatic note does nothing to relieve our family’s extreme distress about his future — his grim expectation of spending the rest of his life in isolation in U.S. prison for publishing award-winning journalism.”

Assange, 52, has been indicted on 17 espionage charges and one charge of computer misuse over his website’s publication of a trove of classified U.S. documents almost 15 years ago. American prosecutors allege that Assange encouraged and helped U.S. Army intelligence analyst Chelsea Manning steal diplomatic cables and military files that WikiLeaks published.

His lawyers say he could face up to 175 years in prison if convicted, though American authorities have said any sentence would likely be much shorter.

Assange’s family and supporters say his physical and mental health have suffered during more than a decade of legal battles, including taking refuge in the Ecuadorian Embassy in London from 2012 until 2019. He has spent the last five years in a British high-security prison.

Assange’s lawyers argued in February that he was a journalist who exposed U.S. military wrongdoing in Iraq and Afghanistan. Sending him to the U.S., they said, would expose him to a politically motivated prosecution and risk a “flagrant denial of justice.”

The U.S. government said his actions went way beyond those of a journalist gathering information and put lives at risk in his bid to solicit, steal and indiscriminately publish classified government documents.

If Assange prevails Monday, it would set the stage for an appeal process likely to extend what has already been a long legal saga.

If the court accepts the word of the U.S., it would mark the end of Assange’s legal challenges in the U.K., though it’s unclear what would immediately follow.

His legal team is prepared to ask the European Court of Human Rights to intervene. But his supporters fear Assange could possibly be transferred before the court in Strasbourg, France, could halt his removal.

The court could also postpone issuing a decision.

If he loses in court, he still may have another shot at freedom.

President Joe Biden said last month that he was considering a request from Australia to drop the case and let Assange return to his home country.

Officials provided no other details but Stella Assange said it was “a good sign” and Australian Prime Minister Anthony Albanese said the comment was encouraging.