Celebrities and supporters of Julian Assange protested in Parliament Square on Saturday ahead of court hearings over his extradition to the United States.
Pink Floyd bass player Roger Waters, fashion designer Vivienne Westwood and former Greek finance minister Yanis Varoufakis were among those in Westminster ahead of Monday's hearing.
The US has charged Assange, 48, with 18 criminal counts of conspiring to hack government computers and with violating an espionage law, all relating to his work with WikiLeaks, which the Australian founded in 2006.
Assange's lawyers are set to argue that extradition and the charges against him are politically motivated.
The hearing at Woolwich Crown Court cannot evaluate Assange's innocence on the charges themselves, but if those charges are seen to be political in nature then his extradition would not be permitted under the UK-US extradition treaty.
WikiLeaks, alongside The Guardian and The New York Times, in 2010 published US military documents and field reports from the Iraq and Afghanistan wars, revealing among other things civilian death counts which had not previously been disclosed.
Shortly after his arrest in London last May, the US Department of Justice
unsealed a grand jury indictment
charging Assange for his "alleged role in one of the largest compromises of classified information in the history of the United States".
Image:Pink Floyd bass player Roger Waters spoke in defence of Assange in Parliament Square
Image:Numerous supporters attended the rally in Westminster
Assange had been effectively trapped in the Ecuadorean embassy in London for seven years before his arrest, with the Ecuadorean government having previously offered him asylum while British police sought him for breach of bail.
Jennifer Robinson, his lawyer, says the extradition and charges which Assange faces in the US could set a precedent for criminalising activities which are crucial for investigative journalists.
John McDonnell: Assange is 'the Dreyfus case of our age'
She added that his work and the material he had published in connection with these charges had revealed evidence of war crimes conducted by the US during the wars in Iraq and Afghanistan.
"They are a remarkable resource for those of us seeking to hold governments to account for abuses," she added.
Image:Julian Assange is being held in Belmarsh Prison ahead of his hearing
In a preliminary hearing last week, the court heard that
Donald Trump had offered to pardon Assange
if he said Russia had not been involved in a leak of emails from the Democratic National Committee (DNC).
Mr Trump has consistently been angered by claims that the Russian government sought to interfere in the 2016 election in his favour.
Special counsel Robert Mueller's investigation into alleged collusion between Donald Trump's presidential campaign and Russia to help him secure a victory resulted in an indictment tying the Russian interference campaign with WikiLeaks.
An indictment
accused 12 Russian military intelligence officers
of hacking into the DNC and Hillary Clinton campaigns and stealing emails which were then published by WikiLeaks as part of the plot to bolster Trump's election.
WikiLeaks is not specifically named in the indictment against the Russian intelligence officers, but the activities described in the legal filing match those of the organisation.
It in turn denied that the emails were provided by a hostile intelligence agency and instead encouraged a conspiracy theory in which they were provided by Seth Rich, a
DNC employee and the victim of an unsolved murder
.