The UK Government has cancelled a working group set up with Ecuador to find a way of resolving the future of Julian Assange, the Australian WikiLeaks founder has claimed.

Foreign Secretary William Hague agreed to the group after meeting Ecuador’s foreign minister Ricardo Patino last year to discuss Assange, who has been living in refuge in Ecuador’s embassy in London for the past two years.

On the eve of the second anniversary of Mr Assange’s dramatic arrival at the embassy, he revealed that the working group was not meeting.

In a conference call from the embassy, the WikiLeaks publisher said a six-member team had been established during Mr Patino’s visit to London with the intention of studying legal and diplomatic issues.

Assange said that following the granting of asylum last year by Russia to US whistleblower Edward Snowden, the UK Government had “unilaterally” cancelled the working group.

Assange has been granted political asylum by Ecuador as he fights to avoid extradition to Sweden, where he faces sex allegations by two women.

He fears that if he goes to Sweden he will be taken to the United States, where a long-running investigation is continuing into WikiLeaks and its involvement with former soldier Chelsea Manning, who has been jailed for 35 years over the leaking of secret intelligence.

Mr Assange has offered to be interviewed by Swedish investigators inside the London embassy, but they have declined to travel to the UK to question him about the allegations.

Jennifer Robinson, a legal adviser to WikiLeaks, said a fresh challenge will be made next week to the Swedish authorities after “new information” was received.

Ms Robinson added that a letter from more than 30 free speech organisations will be sent to the US Attorney General Eric Holder next week calling for him to “close down” the investigation into WikiLeaks.

Assange said Mr Holder should drop the four-year long investigation or resign, accusing him of using “weasel words” when asked about the case.

Asked how he was coping with living inside the embassy, housed in a small building close to Harrods in Knightsbridge, Assange said other people were in far more difficult positions, including Chelsea Manning.