British police have insisted WikiLeaks founder Julian Assange will be arrested if he steps outside the Ecuadorian embassy, where he has been holed up for more than three years.
A United Nations panel is on Friday expected to reveal its ruling that Mr Assange has been "arbitrarily detained" in the embassy, which he entered in 2012 to avoid being extradited to Sweden over sexual assault allegations.
Sweden's Foreign Ministry has confirmed reports on Thursday that the panel has ruled in the 44-year-old Australian's favour.
The British government has declined to comment, but a spokesman for Prime Minister David Cameron says the UN findings are not "legally binding".
"There is a European arrest warrant currently in place and we have a legal obligation to put that into effect," he said.
"(Mr Assange) has never been detained in this country, so there is no arbitrary detention. He is avoiding lawful arrest by choosing to remain in the Ecuadorian embassy," he continued.
In a statement via WikiLeaks on Thursday, Mr Assange said that if he lost his unlawful detention case against the UK and Sweden, "I shall exit the embassy at noon on Friday to accept arrest by British police as there is no meaningful prospect of further appeal".
If Mr Assange does succeed in the UN claim and his detention is deemed unlawful, he said he expected the immediate return of his passport and an end to attempts to arrest him.
Speaking in London, Foreign Minister Julie Bishop said she would keep a "watching brief" on the affair, but added that Mr Assange had not sought consular assistance from Australia for years.
