Australia on Thursday said there was little it could do for WikiLeaks founder Julian Assange after Britain said it had the legal right to raid the Ecuador embassy in London and arrest him.
The former hacker, an Australian national, has been holed up in the building since June in a bid to avoid extradition to Sweden.
Ecuador foreign minister Ricardo Patino said Britain had threatened to "storm our embassy if Ecuador does not hand over Julian Assange".
Assange has repeatedly criticised Canberra's handling of his case, but Australian Attorney-General Nicola Roxon said while she was taking "an absolute interest" in his plight, there were limits to what she could do.
"We've certainly made diplomatic contact and we've obviously been providing consular support as well but ultimately ... this is a matter between Mr Assange and Ecuador," she told ABC radio.
"Increasingly it seems it's a matter between Ecuador and the UK."
Assange faces questioning over sex assault claims in Sweden, but fears Stockholm will turn him over to the US where he could face espionage and conspiracy charges over revelations by WikiLeaks.
Patino said on Wednesday that Ecuador "has made a decision" on whether to grant him asylum and would announce it Thursday at 1200 GMT, while denouncing London.
"Ecuador rejects in the strongest terms the explicit threat made in Britain's official communication," he said.
Don Rothwell, a professor of international law at the Australian National University, said the threat to raid the embassy was unprecedented if true.
"The threat... to invoke the provisions of the Diplomatic and Consular Premises Act 1987 to revoke the diplomatic protection enjoyed by the Ecuadorian embassy in London is extraordinary and without modern precedent," he said.
He added that if Britain went ahead, "Ecuador could rightly view this as a significant violation of international law which may find its way before an international court".
Assange embarked on a marathon round of court battles against extradition, but finally exhausted all his options under British law in June when the Supreme Court denied his final appeal.
He then entered the Ecuador mission.