The international diplomatic row over WikiLeaks founder Julian Assange – who is avoiding extradition to Sweden by taking refuge in the Ecuadorean embassy in London – was escalating as Ecuador continued to push for the support of its South American neighbours.

Having secured an emergency meeting of the Organisation of American States over what Ecuador says is Britain's threat to invade its embassy in London to arrest Assange, the Ecuadoreans are pushing for similar meetings of the Union of South American Nations, the left-leaning Alba association of Bolivarian states and the UN.

On the agenda for the OAS meeting will be both Ecuador's claims that the UK has threatened the principle of "inviolable" status of its embassy in the UK and demands that the UK grant "safe passage" for Assange out of the UK.

As Assange prepared to give a statement on his situation – reportedly outside the embassy, where he could face arrest for breach of his bail conditions – the row over Britain's veiled threat that it could enter the embassy to arrest him appeared to escalate.

On Friday the OAS voted to hold a meeting next Friday following Ecuador's decision to grant political asylum to Assange. Assange has described the move as a "historic victory" but the foreign secretary, William Hague, made it clear that the Australian would not be allowed safe passage out of the country.

The latest developments came as the Australian government released redacted logs under a Freedom of Information request detailing its deliberations over the Assange case. Included in the documents is the Australian government's legal view that any US attempt to prosecute Assange under the Espionage Act – which Assange says he fears – would face "serious obstacles".

The released cables also appear to directly contradict Assange's claims that he had sought asylum with Ecuador because Australia had "abandoned" him by refusing to intervene in his planned extradition.

Officials claim he has been contacted eight times by consular officials while in the embassy. The sources added that far from refusing Assange help, it was Assange who had declined Australian assistance.

Assange has been in the embassy for two months after facing extradition to Sweden to be questioned on claims of sexual assault. He denies the claims and says he fears being sent to the US if he goes to Sweden.

The decision by the OAS to debate the affair follows a letter from the Foreign Office to Ecuadorean authorities, warning it believed it had a legal basis to arrest Assange in the embassy, interpreted by Ecuador as a threat to raid the building – although this has been denied by the UK which says it prefers a "negotiated outcome".

The US, Canada and Trinidad and Tobago opposed the resolution, but 23 members voted in favour of the meeting. There were five abstentions and three members were absent. OAS secretary general José Miguel Insulza said the meeting would be about "the problem posed by the threat or warning made to Ecuador by the possibility of an intervention into its embassy".

He added: "What is being proposed is that the foreign ministers of our organisation address this subject and not the subject of asylum nor whether it should be granted to Mr Julian Assange. That will be discussed between Great Britain and Ecuador. The issue that concerns us is the inviolability of diplomatic missions of all members of this organisation."

Ecuador's president, Rafael Correa, said in a radio interview on Friday that his nation was not trying to undermine Sweden's attempts to question Assange. He said: "The main reason why Julian Assange was given diplomatic asylum was because his extradition to a third country was not guaranteed; in no way was it done to interrupt the investigations of Swedish justice over an alleged crime. In no way."

Hague has said that diplomatic immunity should not be used to harbour alleged criminals. He said it is a "matter of regret" that the Ecuadorean government granted the WikiLeaks founder political asylum but warned that it "does not change the fundamentals" of the case.

The case could go on for some "considerable" time, Hague said, adding: "We will not allow Mr Assange safe passage out of the United Kingdom, nor is there any legal basis for us to do so."

Ecuadorean ministers have accused the UK of threatening to attack the embassy to seize Assange, after it emerged that the Diplomatic and Consular Premises Act 1987 could allow revocation of a building's diplomatic status if the foreign power occupying it "ceases to use land for the purposes of its mission or exclusively for the purposes of a consular post".

But Hague said: "There is no threat here to storm an embassy. We are talking about an Act of Parliament in this country which stresses that it must be used in full conformity with international law."

The Swedish foreign ministry said that it had summoned Ecuador's ambassador over the Latin American country's "unacceptable" decision to grant asylum to Assange.