Embattled WikiLeaks founder Julian Assange is set to face the world's media from the safe haven of London's Ecuadoran embassy but risks arrest if he takes even one step out of the building.
With police officers primed to detain him, Assange must on Sunday find a way of speaking publicly without setting foot outside, raising the possibility of him being forced to speak from a balcony or lean out of a window.
WikiLeaks was tight-lipped about the logistics of Assange's planned appearance at 1300 GMT, with spokesman Kristinn Hrafnsson telling the AFP news agency what little he knew could not be discussed for "security reasons".
But Britain's foreign office warned that the steps to the embassy were considered British territory, and police said officers would take "appropriate action" if he strayed from the building.
Assange, 41, took refuge in the embassy on June 19 to evade extradition to Sweden where he is wanted for questioning over alleged sexual misconduct.
Supporters of the Australian former hacker, granted asylum by Ecuador on Thursday, believe that once in Sweden he could be extradited to the United States.
WikiLeaks' publication of a vast cache of confidential government files has enraged the US government, and Assange's backers fear he could be tried on espionage charges there and possibly face the death penalty.
Despite Ecuador providing a haven for Assange, British Foreign Secretary William Hague has said Britain has no choice but to seek his extradition.
In line with normal diplomatic practice, embassies are considered the territory of the countries they represent, and the host country must seek permission to enter the premises.
Britain has angered Ecuador by suggesting it could invoke the Diplomatic and Consular Premises Act of 1987, which it says allows it to revoke the diplomatic immunity of an embassy on British soil and go in to arrest Assange.
Fewer than 10 police officers and a handful of Assange supporters stood outside the embassy on Saturday.
Ecuador, meanwhile, received powerful backing from regional allies, as they warned Britain of "grave consequences" if it breaches diplomatic security at Ecuador's embassy.
Quito had called on its allies from the Venezuela-led Bolivarian Alliance for the People of Our America (ALBA), whose foreign ministers flew to the Ecuadoran economic capital of Guayaquil and expressed their support.
"We warn the government of the United Kingdom that it will face grave consequences around the world if it directly breaches the territorial integrity of the Embassy of the Republic of Ecuador in London," said a statement issued at the end of the ALBA meeting Saturday.
It also rejected Britain's "threats vis-a-vis our territorial integrity and sovereignty".
Media reports on Saturday said Australian diplomats believed Washington was targeting Assange for possible prosecution on charges including espionage and conspiracy relating to his WikiLeaks whistleblowing site.
But one expert said he believed this was unlikely.
"There is a dose of fantasy in all this," said Chris Brown, a professor of international relations at the London School of Economics.
"The chances of him being extradited to the US from Sweden are non-existent. If the Americans really want him, they would have asked us [Britain] for him," he told AFP.
In 2010, WikiLeaks published hundreds of thousands of US military documents on the war in Iraq and Afghanistan, as well as diplomatic cables that deeply embarrassed Washington.