The complication was that Assange would be required to travel to the US and admit guilt, he said.

“Everything we know about Julian Assange suggests this would be a significant sticking point for him,” Rothwell said.

He added: “It’s not possible to strike a plea deal outside the relevant jurisdiction except in the most exceptional circumstances.”

But Shipton said the idea of his brother travelling to the US to strike a deal was a “non-starter” because of the risk it could lead him to attempt suicide.

“Julian cannot go to the US under any circumstances,” he said.