BRITAIN’S threat to storm Ecuador’s embassy to arrest Julian Assange is hostile and extreme, WikiLeaks says.

Mr Assange sought refuge in the South American country’s London embassy on June 19 to avoid extradition to Sweden, where he is wanted for questioning about allegations of rape and sexual assault.

But Britain is now threatening to revoke the embassy’s diplomatic immunity and take the WikiLeaks founder into custody for breaching his bail conditions.

“A threat of this nature is a hostile and extreme act, which is not proportionate to the circumstances, and an unprecedented assault on the rights of asylum seekers worldwide,” Wikileaks said in a statement on its website on Thursday (AEST).

The UK has no power storm the embassy, it added.

“Any transgression against the sanctity of the embassy is a unilateral and shameful act, and a violation of the Vienna Convention, which protects embassies worldwide,” Wikileaks said.

“This threat is designed to pre-empt Ecuador’s imminent decision on whether it will grant Julian Assange political asylum, and to bully Ecuador into a decision that is agreeable to the United Kingdom and its allies.”

Mr Assange still has not been changed with any crimes in any country.

WikiLeaks joins the government of Ecuador in urging the UK to resolve this situation according to peaceful norms of conduct,” it said.

“We further urge the UK government to show restraint, and to consider the dire ramifications of any violation of the elementary norms of international law.”

The website calls for British Foreign Secretary William Hague to resign if he approved the threat.

Mr Assange, a 41-year-old Australian national, fears he could be extradited to the United States from Sweden to stand trial for espionage over the leaked US diplomatic cables and military logs he published on his whistleblower website.

Ecuador’s president previously has expressed support for Mr Assange and WikiLeaks, and says his asylum application letter impressed him.

But even if the asylum request is granted, it is unlikely he will be able to leave the UK.