The impasse over Julian Assange could be resolved immediately if the UK Government gave an assurance that he would not be extradited to the US if he leaves the embassy where he has been living for more than six years, one of his legal team said on Thursday.

Jennifer Robinson told a conference in Barcelona that the WikiLeaks founder had been under some form of restrictions on his liberty for almost eight years without ever being charged.

He has been living in the Ecuadorian embassy in London since 2012, fearing he will be extradited to the United States for questioning over the activities of WikiLeaks if he leaves.

Ms Robinson, of Doughty Street Chambers, said: “It is difficult to see how this is going to be resolved because of the politics, though the solution is simple.

“We have used every legal avenue available to us, in the UK and at the UN, to challenge this situation.

“This is and has always been about the risk of US extradition. This case could be resolved tomorrow if the UK would give this assurance.”

Speaking at the World Ethical Data Forum, she continued: “For more than eight years we have been fighting a number of landmark cases, in multiple jurisdictions, to protect something we thought was sancrosanct, that perhaps too many have taken for granted: the right to freedom of speech and the freedom of publishers to publish information in the public interest.”

These included the ongoing criminal investigation in the US, which she said was of “unprecedented size and scale”, and the risk of US extradition for Mr Assange, especially as the current US Attorney-General has said prosecuting him was a “priority”.

She also spoke of the financial “blockade”, under which the world’s major credit card companies and payment transfer services banned WikiLeaks, cutting it off from the donations the organisation depends on to operate and to fight its legal battles.

“The new and current challenge of the civil suit filed by the Democratic National Committee (DNC) accusing WikiLeaks of conspiracy and publishing trade secrets for having received information about the DNC and published it in the context of a US election. ”

She raised concerns that “the DNC is seeking to set a precedent with sweeping ramifications for all media, which strikes at the heart of the role of the press in a democracy”.

She added that any prosecution of Mr Assange will be used as a precedent against other media organisations.

“The attacks on WikiLeaks have not just been legal attacks – there has also been a vilification campaign of the WikiLeaks project and of Julian personally by prominent politicians and the mainstream media, and a counter-intelligence operation, openly stated by the director of the CIA last year.”

The Ecuador government cut off Mr Assange’s phone and internet access earlier this year and banned people visiting him.

Weekly vigils are still held outside the embassy and in cities in other countries including his native Australia.