WikiLeaks’ founder Julian Assange’s possible final legal challenge to stop his extradition from Britain to the United States where he is wanted on criminal charges will be held at London’s High Court in February, his supporters said on Tuesday.

Assange, 52, is wanted by U.S. authorities on 18 counts, including one under a spying act, relating to WikiLeaks’ release of vast troves of confidential U.S. military records and diplomatic cables which Washington said had put lives in danger.

Britain has given the go-ahead for his extradition, but he has been trying to overturn that decision. Campaigners said a public hearing would take place at the High Court on Feb. 20-21 when two judges will review an earlier ruling which had refused Assange permission to appeal.

“The two-day hearing may be the final chance for Julian Assange to prevent his extradition to the United States,” WikiLeaks said in a statement.

WikiLeaks first came to prominence in 2010 when it released hundreds of thousands of secret classified files and diplomatic cables in what was the largest security breach of its kind in U.S. military history, which U.S. prosecutors say imperilled the lives of agents named in the leaked material.

Assange’s supporters say he is an anti-establishment hero who has been victimised because he exposed U.S. wrongdoing, and that his prosecution is an assault on journalism and free speech.

He spent seven years holed up in Ecuador’s embassy in London before he was dragged out and jailed in 2019 for breaching bail conditions. He has been held in prison ever since while his extradition case is decided.

His lawyers have also applied to the European Court of Human Rights which could potentially order the extradition to be blocked.

“The last four and a half years have taken the most considerable toll on Julian and his family, including our two young sons,” said his wife Stella, who he married in prison.

“The persecution of this innocent journalist and publisher must end.”