The decision means Mr. Assange does not face immediate deportation. British judges said Mr. Assange could apply to the Supreme Court to hear one specific point of his legal case, but there is no guarantee that the higher court will accept his request.
In his judgment, Judge John Thomas said Mr. Assange had only a small prospect of persuading the Supreme Court of his arguments.
The “chances of success may be extraordinarily slim” for Mr. Assange’s appeal, Judge Thomas said.
Mr. Assange’s lawyers earlier argued that every European arrest warrant issued by police or prosecutors was flawed, because neither should be considered a judicial authority.
Mr. Assange said he was pleased by the ruling.
“The High Court has decided that an issue that arises from my own case is of general public importance and may be of assistance in other cases and should be heard at the Supreme Court,” he said outside the courthouse.
“I think this is the right decision, and I am thankful. The long struggle for justice for me and for others continues.”
“This is positive news for Julian Assange and means he will remain in the U.K. while the court assesses his appeal,” Mr. Assange’s Swedish lawyer, Per E. Samuelsson, said. “It is something we have fought for.”
Claes Borgstrom, the lawyer representing the two women bringing sex-crime charges against Mr. Assange, called the decision regrettable.
“My clients have waited for over a year for a legal conclusion of this, and now they will have to wait even longer,” Mr. Borgstrom said. “Then it will still end with Assange being transferred to Sweden. The rules are very clear about this.”
“I regret he himself doesn’t choose to hand himself over,” Mr. Borgstrom added.
He said the two women had hoped that the last word would be said in the extradition case Monday.
“Now they have to wait for another few months. We are hardened by now, but of course this is still stressful,” he said.
Mr. Assange was accused of rape, coercion and molestation following encounters with two Swedish women in August 2010. Swedish authorities issued a European arrest warrant on rape and molestation accusations, and Mr. Assange was arrested in London in December.
He was released on bail on condition that he live — under curfew and electronically tagged — at a supporter’s country estate in eastern England.
Some of Mr. Assange’s supporters gathered outside the court before the hearing began. One banner draped over railings outside the court read: “Free Assange. Free Manning,” referring to U.S. Army analyst Bradley Manning, who is in custody at Fort Leavenworth prison in Kansas, suspected of disclosing secret intelligence to WikiLeaks.
Associated Press writer Malin Rising in Stockholm contributed to this report.