Lawyers for WikiLeaks founder Julian Assange on Monday failed to persuade a British judge to throw out new US allegations against him, as he resumed his fight to avoid extradition to the United States for leaking military secrets.

Protesters gathered outside London's Old Bailey court as the 49-year-old Australian was brought in, brandishing placards reading "Don't Extradite Assange" and "Stop this political trial".

Inside, Assange's lawyers sought to "excise" new allegations lodged by Washington in recent weeks, saying they had not had time to formulate a proper response.

Assange faces 18 counts from US prosecutors that could see him jailed for up to 175 years
Assange faces 18 counts from US prosecutors that could see him jailed for up to 175 years AFP / Daniel LEAL-OLIVAS

Assange faces 18 charges under the US Espionage Act relating to the 2010 release by WikiLeaks of 500,000 secret files detailing aspects of US military campaigns in Afghanistan and Iraq.

Washington claims he helped intelligence analyst Chelsea Manning to steal the documents before exposing confidential sources around the world.

If convicted, Assange -- who has been held at the high-security Belmarsh Prison for the last 16 months -- could be jailed for up to 175 years.

US authorities recently laid out new evidence against Assange alleging that he and others at the whistleblowing site recruited hackers.

IMAGESSupporters of Julian Assange, including his father Richard Assange, and British fashion designer Vivienne Westwood protest in front of the Old Bailey in London as the extradition trial for the Wikileaks founder resumes.
IMAGESSupporters of Julian Assange, including his father Richard Assange, and British fashion designer Vivienne Westwood protest in front of the Old Bailey in London as the extradition trial for the Wikileaks founder resumes. AFPTV / Mathilde BELLENGER

In court on Monday, defence lawyer Mark Summers protested against the "11th hour" allegations, noting the difficulties Assange already had in communicating with his legal team due to coronavirus restrictions.

"What is happening is abnormal, unfair and liable to create injustice if allowed to continue," he said.

But District Judge Vanessa Baraitser said: "These are issues which must take place in the context of considering the extradition request and not before it."

Assange faces 18 charges under the US Espionage Act
Assange faces 18 charges under the US Espionage Act AFP / Tolga Akmen

Clean-shaven and wearing a dark suit and maroon tie, Assange spoke to confirm his name and date of birth, and said he did not consent to extradition.

It was the first time he has been seen in public since the first part of the hearing in February, when he appeared weak and confused.

The second part of the hearing, due in April, was delayed by the coronavirus pandemic. It is set to last three to four weeks.

Julian Assange has fought his extradition for years
Julian Assange has fought his extradition for years AFP / Vincent LEFAI

Supporters of Assange gathered outside the court, including fashion designer Vivienne Westwood, who said he was "shining the light on all the corruption in the world".

His father, John Shipton, said the hearing was an "abuse trial."

Assange's partner, Stella Moris, took a 80,000-strong petition opposing his extradition to Prime Minister Boris Johnson's Downing Street office, but was turned away.

She has said she feared Assange would take his own life -- leaving their two young sons, who were conceived during his asylum in Ecuador's London embassy, without a father.

US journalism lecturer Mark Feldstein, from the University of Maryland, was the first witness to be called in the hearing, giving evidence via videolink.

He said leaks of classified information, either to the media or Congress, were commonplace.

"Leaks shed light on decision-making by the government and inform the public powerfully, but they also expose government deceit, corruption and illegality and abuse of power," he told the court.

At the February hearing, James Lewis, representing the US government, said WikiLeaks was responsible for "one of the largest compromises of classified information in the history of the United States".

"Reporting or journalism is not an excuse for criminal activities or a licence to break ordinary criminal laws," he added.

The extradition hearing is the latest in a series of legal battles faced by Assange since the leaks a decade ago.

In 2010, he faced allegations of sexual assault and rape in Sweden, which he denied.

He was in Britain at the time but dodged an attempt to extradite him to Sweden by claiming political asylum in Ecuador's embassy in London.

Swedish prosecutors confirmed last year they had dropped the rape investigation, saying that despite a "credible" account from the alleged victim there was insufficient evidence to proceed.