The world's media gathered outside the Ecuadorean embassy in London's Knightsbridge today. Cameras jostled for space and reporters crowded the pavements, at times blocking traffic, as they waited to see if Julian Assange would emerge from the building. The odd customer coming out of Harrods, the upmarket department store, stopped to join the fray, asking in whispers what people were waiting for.

The furore was trigged by the UN Working Group on Arbitrary Detention (UNWGAD), based in Geneva. On Friday, the group said in a statement that "the various forms of deprivation of liberty to which Assange has been subjected constitute a form of arbitrary detention."

A small number of WikiLeaks supporters, who have kept vigil for Assange since he arrived at the embassy in 2012, attracted throngs of journalists, battling to get the best camera angle. Former Spanish teacher Elsa Collins addressed the assembled reporters through a megaphone, declaring that the UK government was detaining Assange illegally. Later, another supporter silently held up a copy of the WikiLeaks files.

Inside the embassy, Assange addressed the world's media via Skype, speaking to a press conference being held in west London. He declared that Britain's foreign secretary had "insulted" the UN by rejecting the panel's findings. "This is the end of the road for the legal arguments put forward by Sweden and the UK," he said.

Assange claimed asylum in the Ecuadorean embassy in 2012. He wanted to avoid extradition to Sweden over a rape claim that he denies. Assange believes that if he is extradited to Sweden, he could be extradited in turn to the US where he could face charges over his organization WikiLeaks' sharing of confidential state documents. Entering the embassy was a violation of his bail conditions in the UK, meaning that he faces arrest if he steps outside. The stand-off has cost the British taxpayer 12 million pounds (16 million euros/$17 million) on policing.

In 2014, Assange complained to the UN panel that he was being "arbitrarily detained" as he could not leave the embassy without being arrested. He argued that living in 30 square meters of the embassy with no sunlight or fresh air had taken a "significant toll" on his mental and physical health.

"The UN body issued its decision after a 16-month independent review that took into account all evidence submitted by Sweden and the UK," Carey Shenkman, Assange's US human rights lawyer, told DW. "We now look to both countries to implement the reported decision in accord with their obligations under international law."

Standing firm

Yet the authorities are not backing down. As details of the UNWGAD's decision were leaked on Thursday, the Metropolitan Police issued a statement reiterating that Assange would be arrested if he left the embassy. Swedish prosecutors, too, said that the UN panel's decision would have "no formal impact" on its ongoing investigation.

"We have been consistently clear that Mr Assange has never been arbitrarily detained by the UK but is, in fact, voluntarily avoiding lawful arrest by choosing to remain in the Ecuadorean embassy," a spokesman for Downing Street told DW. "The UK continues to have a legal obligation to extradite Mr Assange to Sweden."

Given this context, what difference will the decision make to the long legal stand off? Legal opinions are divided. Understandably, Assange's legal team are playing up the significance. "I would call the decision a game-changer," says Shenkman. "It means Sweden and the UK need to fix this situation and compensate Mr Assange for the injury caused to him. To date neither country has offered Mr Assange a process that takes into account his asylum."

Not binding

Others point out that - contrary to Assange's press statement Friday - the UN panel's decision is not legally binding. "It is an advisory opinion with no legal effect," said UK legal commentator David Allen Green. "Had the decision gone the other way, that would not have made any legal difference either. It's not entirely irrelevant - it's a document which Assange could refer to in court, to support or evidence a point, but it would not by itself make any legal difference."

The reasoning of the UN panel has also been called into question, not just by the British and Swedish authorities, but by a number of legal experts. "Ironically, they seem to have adopted an arbitrary definition of arbitrary, and also of detention," said Green. "Arbitrary here should mean this is Kafkaesque or inconsistent with what you would reasonably expect. It is not. He was able to appeal all the way up to the Supreme Court and all he had to do was comply with bail conditions. The detention is entirely at his own will - he's a fugitive. He can walk out at any point. Nothing is stopping him. But once out he will just have to obey the law of the land."

Of course, neither the UK nor Sweden will want to appear to go against a UN decision. "The ball is in Sweden's yard, in the prosecutor's yard," said Assange's Swedish lawyer, Per Samuelsson. "She is not formally bound by the decision by the UN, but morally it is very difficult to go against it."

As the press conference drew to a close and rain started to fall on this typically grey London February day, it became apparent that after nearly four years inside the embassy, Assange was not going to risk arrest by the waiting police officers outside.