Mr Christensen and independent MP Andrew Wilkie visited the 48-year-old Australian for an hour-and-a-half in Belmarsh prison near London on Monday, one week ahead of his US extradition trial.

Assange is facing up to 175 years in a US prison on 17 spying charges and one conspiracy to commit computer intrusion charge over his organisation's release of classified American diplomatic cables and Pentagon files on the Iraq and Afghanistan wars, some of which revealed US war crimes.

Mr Christensen says the Australian government has so far been reluctant to be involved, but after "certain facts" of the case come light in the trial they will act.

"There is more the Australian government can do, and I think when we hear some of the stuff that's going to come to light next week, there's more that will be done," he said.

Mr Christensen, who was also briefed by Assange's legal team, indicated the public's perception of the case will also shift.

"There's information that I now know, that will be known next week, that will probably make people sit up straight and worry about this a hell of a lot," he said.

"And I think that now is a time that the government that I'm part of needs to be standing up and saying to both the UK and the US: 'enough is enough, leave our bloke alone and let him come home'."

Mr Wilkie said the trial will allow the public to learn the facts rather than "the allegations, the innuendo, the misinformation, the disinformation" about Assange.

"When they are able to look at the facts, they are almost universally coming to the conclusion that a great injustice is being done," he said.

Both politicians described Assange as "a man under serious pressure" given his confinement and the possible sentence awaiting him in the US.

They also had no reason to doubt UN Special Rapporteur on Torture Nils Melzer's assessment that the Australian has suffered psychological torture.

"What I have seen today probably proves there has been ongoing issues, isolation being one of them, that has taken place in this prison behind us, that probably led to a depleted, or less than normal state of mind he is in now," Mr Christensen said.

"I got a feeling of disorientation. About a range of different things. He obviously has no idea about what is going on in the outside world."

Mr Wilkie senses that Assange feels betrayed by the Australian, British and US governments.

"I actually think he's holding it together remarkably well; I think he's a man of inner strength," he added.

Australian Associated Press