Julian Assange's mother on Thursday claimed the United States was behind a British threat to raid the Ecuador embassy in London and arrest her son, as Australia said there was little it could do to help him.
The WikiLeaks founder, 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's mother Christine said she was furious that British police may be sent in to seize him, and claimed they would be acting on behalf of Washington.
"What the US wants, the US gets from its allies, regardless of if it's legal or if it's ethical or in breach of human or legal rights," she told reporters in Australia.
"We're all lackeys."
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 his whistleblowing website.
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.
Christine Assange called on Australian Attorney-General Nicola Roxon to protest the threat.
The former hacker has repeatedly criticised Canberra's handling of his case, but 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."
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.