Ecuador is set to announce Thursday whether it will grant asylum to WikiLeaks founder Julian Assange, who has sought refuge in the country's embassy in London since late June.

The decision comes amid heightened diplomatic tension after Ecuador accused Britain on Wednesday of threatening to storm the embassy in order to arrest Assange.

Britain says it will not allow Assange safe passage out of the country and has an obligation to extradite him to Sweden where he is wanted for questioning in connection with sexual assault allegations. He has denied those claims.

Britain's Foreign Office said in a statement that officials have clarified portions of relevant British law to Ecuador. Western media outlets quoted unnamed British officials as citing the possibility of revoking the embassy's diplomatic immunity.

Assange fears Sweden could send him to the United States to face possible charges related to the 2010 release of hundreds of thousands of classified documents, including diplomatic cables held by the State Department about the wars in Iraq and Afghanistan.