In late 2010, payments firms including Visa, MasterCard and PayPal began blocking donations to WikiLeaks in response to its decision to start publishing US State Department cables.

Within a year, the whistle-blowing site shut down publication to concentrate on fighting the 'financial blockade' it claims has cut off 95% of donations, costing it more than $20 million.

Last July, the Julian Assange-fronted outfit claimed a victory in one of its legal battles when an Icelandic court ruled that Valitor (formerly Visa Iceland), violated contract laws by blocking credit card donations.

The case involved WikiLeaks' Icelandic credit card processing partner DataCell, which inked a deal to process donations with Valitor in June 2011. The gateway was tested, certified and opened by Valitor but then promptly closed "without any plausible explanation," says WikiLeaks.

The court ordered Valitor to reopen the gateway within 14 days or face daily fines of IKr800,000.

Valitor appealed but the decision has now been upheld by Iceland's Supreme Court which has reiterated the threat of daily fines of around $6830 a day if the gateway is not reopened within 15 days.

WikiLeaks claims that the ruling will strengthen its hand in other litigation, including a similar case it is working on against a Danish sub-contractor for Visa, equivalent to Valitor.

Says Assange: "This is a victory for free speech. This is a victory against the rise of economic censorship to crack down against journalists and publishers

"We thank the Icelandic people for showing that they will not be bullied by powerful Washington backed financial services companies like Visa. And we send out a warning to the other companies involved in this blockade: you're next."