WikiLeaks founder Julian Assange will be allowed to seek a Supreme Court appeal against his extradition to the United States.
In December, following a successful appeal by the US government, the UK's High Court ruled he could be extradited to face 18 charges including espionage.
However, the same judges have now found Assange's case contains a point of law of general public importance.
That means he can now seek leave to appeal to the Supreme Court, the country's highest court.
Assange, 50, has been in Belmarsh prison since April 2019, when he was dragged out of the Ecuadorian embassy where he had lived for seven years.
The Australian faces 18 charges over the release of thousands of classified US documents, many relating to the wars in Iraq and Afghanistan.
The US argues the leaks endangered lives, but Assange's supporters say the disclosures were in the public interest.
While the judges refused him permission for a direct appeal to the Supreme Court on their decision, they said his case raised an issue of legal importance that he could ask the United Kingdom's top court to rule on.
"The respondent's application to certify a point of law is granted," the judges said in their pronouncement.
"The respondent's application for leave to appeal to the Supreme Court is refused."
This means the Supreme Court will have to decide whether or not it should hear his challenge.
The judges said the issue of whether the High Court could rely on US assurances about Assange's treatment, which had not been given in the initial proceedings, was a subject on which his legal team could seek clarification.
"Whether or not the issue needs ventilation in that court is a matter appropriately for its decision," they said.
"We would respectfully invite the Registrar of the Supreme Court to take steps to expedite consideration of any application for leave to appeal which follows."
Assange has 14 days to make an application to the court.
His fiancee, Stella Moris, said she was pleased about the decision but Assange was still a long way from achieving justice.
"Make no mistake, we won today in court," she said.
In January last year, Westminster Magistrates' Court blocked Assange's extradition due to concerns for his mental health.
That decision was overturned on appeal in December after the US offered assurances that he would not be held in solitary confinement and could serve his sentence in Australia.
However, Assange's lawyers argued those assurances were meaningless because they could be reversed.
ABC/wires
