Wikileaks founder Julian Assange has appeared in the dock at London’s Old Bailey court as he fights his extradition to the United States.

The 49-year-old Australian appeared clean shaven in court on Monday, with spectacles perched in his short cropped hair.

He wore a smart dark suit, maroon tie and white shirt.

Assange spoke to confirm his name and date of birth at the start of the hearing.

He formally said he did not consent to extradition, following a fresh indictment lodged in the US.

Julian #Assange lawyer says extradition to US should be prevented by UK law because it is directed at #Wikileaks founder's “political views” and he faces discrimination on “grounds of ‘political opinions’ and his foreign nationality”.

— David Brown (@DavidhBrown) September 7, 2020

Assange has been in high-security Belmarsh Prison for 16 months and is wanted in the US over the publication of hundreds of thousands of classified documents in 2010 and 2011.

He is facing 18 charges, including plotting to hack computers and conspiring to obtain and disclose national defence information.

The allegations include that Assange conspired with army intelligence analyst Chelsea Manning to crack a scrambled password, known as a “hash”, to a classified US Department of Defence computer.

If convicted, he faces a maximum possible penalty of 175 years in jail.

A group of 117 doctors and psychologists wants an end to “the psychological torture and medical neglect of Julian Assange”. Photo: AAP

Assange’s supporters have accused the US administration of targeting Assange for “political” reasons after WikiLeaks exposed alleged war crimes and human rights abuses.

Dozens of supporters, including his father, John Shipton, gathered outside the Old Bailey on Monday, where a small stage has been erected for a planned protest.

Demonstrators roared in applause as speeches demanded the British government free Assange.

Outside @10DowningStreet with @StellaMoris1 and @cmihr to deliver @RSF_inter’s petition with more than 80,000 signatures calling on the UK authorities not to extradite @wikileaks publisher Julian Assange to the United States. #FreeAssange pic.twitter.com/iqmj4IlscU

— Rebecca Vincent (@rebecca_vincent) September 7, 2020

Earlier on Monday Assange’s partner Stella Moris arrived at Downing Street in a bid to deliver a Reporters Without Borders petition against the extradition, which has been signed by around 80,000 people.

Last month, she launched a Crowdjustice campaign to help fund his defence which has now topped £100,000 ($182,000).

Speaking on Sunday, Ms Moris, who has two young sons with Assange, described the possible impact on their family.

“To the boys, Julian has become a voice on the telephone, not their father whom they can see and hug,” Ms Moris said.

“It is heartbreaking to think that if Julian is extradited and put in a US super-max prison, the boys will never get to know their father and he will never see them grow up.

“Julian’s case has huge repercussions for freedom of expression and freedom of the press. This is an attack on journalism.”

It is expected dozens of witnesses will be called over four weeks.

Assange has been held on remand in Belmarsh since last September after serving a 50-week jail sentence for breaching his bail conditions while he was in the Ecuadorian embassy in London for almost seven years.

-AAP