Britain's Supreme Court has ruled Australian-born WikiLeaks founder Julian Assange can be extradited to Sweden.
The seven judge panel ruled five to two that Mr Assange's extradition appeal be dismissed and he be extradited to Sweden.
The panel has ruled Sweden's prosecutor is a judicial authority and thus the European arrest warrant is valid.
"The request for Mr Assange's extradition has been lawfully made and his appeal against extradition is accordingly is dismissed," Supreme Court president Judge Nicholas Phillips said on Wednesday.
Swedish authorities argued before the hearing that if his appeal is granted it could throw the fast-tracked European arrest warrant system into turmoil, with implications across the continent.
A Swedish prosecutor wants to question Mr Assange over allegations he sexually assaulted two women in August 2010.
Mr Assange has previously said the sex was consensual, and says the allegations are politically motivated.
The claims followed Mr Assange's release of a swathe of leaked US diplomatic cables that embarrassed governments and international businesses.
Mr Assange fears he may be extradited to the United States from Sweden.
In a surprising absence, Mr Assange was not present in the court today to hear the verdict. One of his supporters, journalist and filmmaker John Pilger, said he was "stuck in traffic" with his mother Christine, who flew in from Australia for the verdict.
Christine Assange said ahead of the judgement: "It's a 24-hour nightmare because we know he is not safe and the biggest governments in the world are gunning for him."
Mr Assange's defence team has been granted a two-week stay to decide whether to appeal against a particular point of law.
If this is denied, Mr Assange's last lifeline will be the European Court of Human Rights.
One of his lawyers, Jennifer Robinson has told ABC News 24 the Supreme Court's decision is "not altogether unexpected".
Ms Robinson says "it remains to be seen" what the next options are.
She also says she has received a letter from Attorney-General Nicola Roxon saying she has no knowledge about US plans to charge Mr Assange.
US Ambassador Jeffrey Bleich agrees, claiming there is "absolutely no basis for the US to be interested in this, we're not involved".
But Greens Senator Scott Ludlam says the Australian Government could be doing more to help Mr Assange.
"I think the Australian Government has been extremely weak and they need to decide whether their allegiances are with Washington or the Australian public, which is, as someone has already said, actually very strongly in support of Julian and his colleagues," he said.
The Swedish lawyer for Mr Assange's alleged victims says he expects Mr Assange will be extradited to Sweden sooner or later.
"[Today's] decision was what we expected," lawyer Claes Borgstroem said.
"It's unfortunate that it has been delayed further, but he will ultimately be extradited.
"We expect an indictment fairly soon after he gets here, maybe within a month."
One week ago, Mr Assange attended a film screening in London wearing a Kevlar Guy Fawkes mask.
"This may be my last time in public, so I thought I should start with a situation where you won't be able to see me anymore," said Mr Assange, who since December 2010 has been forced to report to police daily and wear an electronic ankle tag.
A lower court in Britain initially approved Mr Assange's extradition to Sweden in February 2011.
An appeal to the High Court was rejected in November, but Mr Assange subsequently won permission to appeal to the Supreme Court, which heard two days of complex arguments in February.